The 26-year-old from Puerto Rico has the best pitch for the perfect first 'Survivor' day of everyone on the 'Ghost Island' cast, and it's really not close.

Welcome to the Survivor: Ghost Island preseason! THR's Josh Wigler reports from his visit to the show's shooting location on Fiji, where he interviewed host Jeff Probst, as well as the 20 new castaways battling it out for the million-dollar prize.

Click here to make sure you're all caught up on our stories from the island, including our weekly podcast series "First One Out: Ghost Zero," an in-depth look at all of the new players, culminating in an interview with the first person voted out of the season, and Wigler's exclusive overnight stay on Ghost Island.

First thing to know about Stephanie Gonzalez: She's not the only Stephanie on the season. Heck, she's not the only Stephanie in her tribe. "We don't love that we have two Stephanies [in the same tribe], but that was the best tribe division," says executive producer and host Jeff Probst. Since the time of this interview, the Malolo Tribe and Survivor at large have solved the Stephanie dilemma: This one will go by her last name, Gonzalez, grandfathered into the illustrious group of Survivor alumni whose first names have been checked at the door.

"She's a shit-talker, a tomboy, seems like she knows how to work men," says Probst. "She works in her family business. A lot of what she does appears to rely on her ability to get people to stop and talk to her. If all those skills are honed? Those are some great Survivor skills. To be able to talk to somebody where they are and not have them always have to come to you? To get them to stop and say, 'Yes?' That seems like a pretty decent skill."

Gonzalez, a Florida resident by way of Puerto Rico, is someone who gives a certain Survivor reporter's love for pizza a run for its money. More about that in our interview below, and hear even more from Gonzalez and the other players in the fourth episode of our preseason podcast series, First One Out: Ghost Zero.

The Survivor players Gonzalez wants to emulate: "I think I'm a combination of a couple of people. I'll probably play a little with my heart, like Andrea does. She connects with people on a genuine level. I like how enthusiastic and over the top Zeke is about everything. He's such a storyteller. You feel like you're there, and it's so vivid with everything he says — his emotions and his interpretations of people. He's a smart player. I'll probably be a more social player like Zeke. I loved the first time Michaela played. Such a badass game. The girl is built like an ox. Obviously, telling everybody her plan at the end with the seashells? That didn't work out so well." Gonzalez's first day on Survivor, if it goes perfectly: "Perfectly for me? OK… I don't know if you want to hear this! OK. First day. Jeff goes, 'Alright, Survivors.' He sets us off. We jump off the ship. We're swimming. Of course, I'm leading my whole 10 people. I'm first. Maybe even pulling the raft, very heroic of me. I build our fort, and everyone is looking at me: 'Thank you so much, Stephanie! Wow, you're just amazing!' All of a sudden I find a pizza box lying in the middle of nowhere. It's a fresh mushroom and onion pizza. I take a bite of the pizza and it's delicious. And there's a margarita next to the pizza! This is my perfect day. I eat it all, because I don't want to share. It would be terrible for them, too. Pizza is bad for you. I'm going to sacrifice my body to eat the pizza. And the margaritas, too. So I get back. People are like, 'Stephanie, thank you for eating that pizza. We really appreciate you.' And then Jeff comes out and says, 'Guys, this is all a joke. Stephanie, I'm going to give you that check for the money right now, save everyone some time and heartache.'" Gonzalez's ethical philosophy on Survivor: "Survivor is kind of great in the sense that you see people go one way or the polar opposite. Where we need to be in order to win — and I'll have to prove myself on this point — is you have to be right in the middle, where you're still human enough to make connections, and you're not going to let those connections blur your decisions at the end of the day. You're there for a goal. When you have a goal that big, you can't lose focus and stir people away from it, just because you're letting your feelings get in the way. I want to connect with everybody, and I want to make sure I'm creating a positive thought of myself in their brain — but at the end of the day, you gotta go. Let's put you on the jury so at the end of the day, you give me your vote." How Gonzalez will react if she's blindsided: "Losing… that word is not in my vocabulary! I do not lose. I cannot lose. I'm here to win. I will probably be a little butt hurt, to be frank. I'll probably respect the person. They might get my vote [to win] if they did a good enough job. It has to be orchestrated gorgeously for me to have that respect towards them, otherwise, no."

That's Gonzalez in her own words. But what do the other castaways think about her? Over the course of our interviews out ion Fiji, the Ghost Island castmembers were presented with pictures of their competitors, and asked to establish their preseason thoughts. With that said, here's what they think about Gonzalez.

Donathan Hurley (Caretaker, Malolo Tribe): "I haven't had a chance to look at her much. She's not one who runs around a lot. She really sits in the same spot and I try to jump from table to table."

Chelsea Townsend (Cheerleader and EMT, Naviti Tribe): "I'm not sure what to think about her. She's kind of kept to herself. She hasn't been super friendly around Ponderosa. Most people smile as they walk by, nodding sort of like, 'Well, this is super awkward! Can't wait until we can actually speak! See you later!' It's all said in the eyes as you walk by. She's one of the people who I'm not sure if she's worried about any interaction whatsoever, because she just walks right past you. I don't know if it's a personality thing or just the situation."

Kellyn Bechtold (Career Counselor, Naviti Tribe): "She doesn't seem to be engaging with the process. She's kept to herself. I don't see her being a fan of Survivor. That just doesn't seem like what she does on Wednesday nights, on White Rice Wednesdays. I bet she doesn't even know who Keith Nale is! That sounds harsh, and I don't mean it that way, but I'm just wondering why she's here. I'm curious about what her story is."

Laurel Johnson (Financial Consultant, Malolo Tribe): "Another one where I'm not sure what she's doing here. She's been full hair and makeup every day here at Ponderosa. That's not what we're here for, right? I don't know if we'll get along well together."

Brendan Shapiro (Physical Education Teacher, Malolo Tribe): "She's a little bit of a loner. She keeps to herself. We all have to keep to ourselves, but she really keeps to herself, separate from everybody else. It'll be interesting to see if she plays it that way out here. If she does, she'll be in trouble."

Bradley Kleihege (Law Student, Naviti Tribe): "The nickname I gave her [at casting finals] is 'Trouble.' She's attractive, she looks like someone who would totally stab you in the back. Much like [Angela], she looks very grumpy, almost like she's pissed to be here. It's weird. It's not something I would really want to work with."

Angela Perkins (Army Veteran, Naviti Tribe): "She looks like she could be a competitor. Maybe a little abrasive. She's going to tell you what's on her mind, and she's going to get pissed. I think her inner circle is her inner circle. I don't think she has an outer circle. When you do something bad, she's going to let you know, and she's not going to let it go."

Libby Vincek (Social Media Strategist, Malolo Tribe): "She's exotic, like Abi. I feel like she's going to have an attitude. She's definitely going to be somebody who will be interesting to have on a tribe."

James Lim (Business Analyst, Malolo Tribe): "I can see her maybe being the Abi-Maria of our season, the drama queen. Hopefully, I'm wrong with my first impression, but she seems to have the potential for a lot of sass. If she doesn't like how things are going, she will let people know. If you let me know in that way? I'll listen. I'll let you do you. I'll work with it. But I see some drama there."

Morgan Ricke (Marine Animal Trainer, Naviti Tribe): "She seems hardheaded and stubborn. That's about all I've got. She never really smiles that much at anyone. She kind of stares at you. What are you thinking about me?"

Wendell Holland (Furniture Company Owner, Naviti Tribe): "I haven't seen much from her. She has a few tattoos. She's a pretty girl. Doesn't seem like she's super gamey. She's probably an easy target to get out early. We'll see."

Jenna Bowman (Advertising Account Executive, Malolo Tribe): "A little Latina flair. She's kind of sexy. She'll flirt her way through the boys. I don't know about an alliance."

Domenick Abbate (Construction Supervisor, Naviti Tribe): "The diva. I'm not a fan of hers. She seems moody. She seems like she's going to be annoying people early. Why I have that impression? I cannot tell you. Just sitting next to her for 10 minutes one day this week, I was like, 'No. You gotta go.' I don't know. She has some whacky tattoo. I don't know. It could be anything. I could be completely wrong. She could be a nun! Who knows?"

Jacob Derwin (Music Teacher, Malolo Tribe): "We had a funny moment in the airport on the way over and we shared a laugh. Someone knocked into the back of my leg with some rolling thing, and I legitimately jumped. I turned around and she stuck out her bottom lip and started laughing, and I was just like, 'Pardon!' She could be really lovely."

Michael Yerger (Real Estate Agent, Malolo Tribe): "She's gorgeous. I thought we might have better chemistry, but there's nothing there so far. I think she doesn't want to give away too much before everything starts to get going. That's just my first read on her. She seems closed off and a little hard to interact with. If her gameplay is like that at all, it might be difficult for her."

Chris Noble (Male Model, Naviti Tribe): "That's Mrs. Smith. I think she's probably Puerto Rican. My guess is she's from Florida. I'm from Florida and I love Latinas, and Latinas love me. I don't have much of a vibe on it. I could easily see it being a very quick bond. It could even be too dangerous of a bond. I'm going to want to middle-school make-out with her, right off the bat. I'm going to want to grab her face and put my lips on hers."

Josh Wigler (Reporter, THR): "Free advice: Rein it in."

Stephanie Johnson (Yoga Instructor, Malolo Tribe): "She's hot. She's a total babe. She looks like one of my best friends back home. She looks like she could be a runner to me, and since I'm a runner, I feel like there could be a connection. I'm not giving away that I'm a runner, but I can talk the lingo and say I've run a couple of 5Ks and try to bond with her over that."

Sebastian Noel (Fishing Guide, Naviti Tribe): "Another interesting one. She has very particular tattoos. She has a compass. She has Roman numerals on her spine. She has a butterfly underneath her ear. She might be very spiritual. I work well with spiritual people. My mom is spiritual. I think we could work well with each other."

Desiree Afuye (Student, Naviti Tribe): "I think I can work with her. I think we can put our heads together and really be the terrible two."

Keep up with all of our preseason interviews:

• Angela Perkins

• Bradley Kleihege

• Brendan Shapiro

• Chelsea Townsend

• Chris Noble

• Desiree Afuye

• Domenick Abbate

• Donathan Hurley

• Jacob Derwin

• James Lim

• Jenna Bowman

• Kellyn Bechtold

• Laurel Johnson

• Libby Vincek

• Michael Yerger

• Morgan Ricke

• Sebastian Noel

• Stephanie Gonzalez

• Stephanie Johnson

• Wendell Holland

What's your read on Gonzalez? Sound off with your predictions in the comments section below, and keep checking THR.com/Survivor for more interviews with the Survivor: Ghost Island cast.


Background {#Sec1}
==========

There are approximately one million new cases of gastric cancer (GC) each year worldwide, and half of them occur in Eastern Asia, including China, Japan, and South Korea \[[@CR1]\]. Despite advances in early screening and comprehensive treatment of GC, it remains the third most common cause of cancer-related death in the world \[[@CR2]\]. For advanced GC, a consensus has been reached of radical gastrectomy with D2 lymphadenectomy \[[@CR3]\]. However, there is still controversy over the number of retrieved lymph nodes (RLNs) for accurate pathological staging.

Several studies have reported that RLN count was positively correlated with better overall survival in GC, even in lymph node-negative GC \[[@CR4]--[@CR7]\]. An RLN count of ≥ 16 has been recommended by the 8th edition TNM classification for GC to guarantee the accurate pN stage \[[@CR8]\]. Moreover, Okajima et al. suggested an optimal RLN count of ≥ 25 for nodal staging \[[@CR9]\]. Recently, by stratum analysis of 7620 patients, Deng et al. proposed an optimal RLN count of ≥ 16 for lymph node-negative GC and \> 30 for lymph node-positive GC \[[@CR10]\]. These above studies are all conducted by comparing the RLN count with long-term survival. But little is known about the relationship between the RLN count and short-term complications after radical surgery.

Postoperative complications of GC pose a significant impact on the length of postoperative stay and hospital charges, which further affect the quality of life \[[@CR11]\]. Therefore, investigating the relationship between RLN count and postoperative short-term complications would provide more comprehensive evidence for selecting the appropriate RLN count.

Methods {#Sec2}
=======

Patients {#Sec3}
--------

A total of 1487 consecutive GC patients between January 2016 and December 2018 at Nanjing Drum Tower Hospital were retrospectively reviewed. All patients underwent curative (R0) gastrectomy and were histologically confirmed. The exclusion criteria were as follows: (1) multivisceral resection, (2) patients accepting preoperative radiotherapy or chemotherapy, (3) patients with previous stomach surgery, and (4) patients with incomplete clinical data. This study was approved by the Ethics Committee of Nanjing Drum Tower Hospital.

Data collection {#Sec4}
---------------

Data for preoperative characteristics, intraoperative index, and postoperative features were extracted. Preoperative characteristics included age, gender, body mass index (BMI), comorbidities, and laboratory data. The intraoperative index involved the American Society of Anesthesiologists (ASA) grade, surgical approach, type of resection, operation time, and blood loss. Postoperative features included depth of tumor invasion, tumor site, retrieved lymph node count, lymph node metastasis, lymph node ratio (LNR), log odds of positive lymph nodes (LODDS), pTNM stage, Lauren subtype, short-term complications, postoperative stay, and total hospital charges. LNR was defined as the ratio of positive to retrieved lymph nodes. LODDS was calculated by log \[(positive lymph nodes + 0.5)/(total lymph nodes − positive lymph nodes + 0.5)\] \[[@CR12]\]. The postoperative short-term complications occurring in the hospital or within 30 days were collected. All complications were evaluated according to the Clavien-Dindo classification system \[[@CR13]\].

Statistical analysis {#Sec5}
--------------------

Statistical analyses were conducted by SPSS 19.0 (Chicago, IL, USA). Continuous variables were shown as means ± SD. Student's *t* test was applied for normally distributed data; Mann-Whitney *U* test was applied for non-normally distributed data. Categorical variable data were presented as numbers and analyzed using the chi-squared test or the Fisher exact test. Univariate and multivariate analyses were performed to analyze the risk factors associated with the postoperative complications or retrieved lymph node count. The optimal cutoff values of LNR and LODDS were determined by receiver operating characteristic (ROC) analysis. All statistical tests were conducted two-sided, and statistical differences were termed as *P* value \< 0.05.

Results {#Sec6}
=======

Patient characteristics {#Sec7}
-----------------------

The background characteristics of the patients enrolled in this study were presented in Table [1](#Tab1){ref-type="table"}. There were 1487 GC patients in all, including 1089 (73.2%) men and 398 (26.8%) women. The median age was 60 years with a range from 21 to 96 years. A total of 1411 (94.9%) patients underwent open gastrectomy while 76 (5.1%) underwent laparoscopic surgery. The type of resection was distal gastrectomy in 617 (41.5%) patients, proximal gastrectomy in 163 (11.0%), and total gastrectomy in 707 (47.5%). The mean operation time was 232 min, and the mean intraoperative blood loss was 221 ml. Pathological results were stage I/II/III/IV in 506/368/597/16 patients, respectively. The mean RLN count was 25.1 (range, 2--84), and 864 (58.1%) patients were tested with lymph node metastasis. Overall, postoperative short-term complications occurred in 435 (29.3%) patients. The mean postoperative stay was 12 days, and the mean total hospital charges were 7.5 × 10^4^¥. Table 1Demographic and clinical features of patientsCharacteristics*N* = 1487Age (years)60.4 ± 17.3Gender (*n*) Male1089 Female398BMI (kg/m^2^)23.0 ± 3.5Preoperative comorbidities (*n*) Previous abdominal surgery209 Diabetes mellitus131 Hypertension488Preoperative laboratory data Serum albumin (g/L)39.4 ± 3.3 CRP (g/L)6.0 ± 12.4ASA ≥ 3884Mode of surgical approach (*n*) Laparoscopic76 Open1411Type of resection (*n*) Distal gastrectomy617 Proximal gastrectomy163 Total gastrectomy707Operation time (min)232.3 ± 61.8Blood loss (ml)221.8 ± 204.5Tumor invasion T1--2631 T3--4856Tumor site Cardia/fundus452 Body381 Pylorus/antrum654RLN count25.1 ± 9.1Lymph node metastasis Positive864 Negative623LNR0.17 ± 0.24LODDS− 0.96 ± 0.75pTNM stage I/II/III/IV506/368/597/16Lauren subtype Intestinal620 Diffuse428 Mixed401 Unknown38Postoperative complications Positive435 Negative1052Postoperative stay (days)12.0 ± 8.1Total hospital charges (10^4^¥)7.5 ± 3.5*BMI* body mass index, *CRP* C-reactive protein, *ASA* American Society of Anesthesiologists, *RLNs* retrieved lymph nodes, *LNR* lymph node ratio, *LODDS* log odds of positive lymph nodes

Association between perioperative characteristics and postoperative complications {#Sec8}
---------------------------------------------------------------------------------

As presented in Table [2](#Tab2){ref-type="table"}, univariate and multivariate analyses indicated that postoperative short-term complications were significantly correlated with age, gender, level of preoperative serum albumin, and operation time. Stratified analyses by type of resection revealed that complications occurred frequently in proximal gastrectomy compared with total gastrectomy, while there was no significant difference between distal gastrectomy and total gastrectomy. No significant association was observed between RLN count and overall postoperative complications. Table 2Univariate and multivariate analyses of characteristics associated with postoperative complicationsCharacteristicsUnivariateMultivariateOR95% CI*P*OR95% CI*P*Age ≥ 701.5811.232--2.029\< 0.0011.5781.219--2.0440.001Gender Male0.7650.597--0.9790.0330.7100.551--0.9160.008 FemaleBMI (kg/m^2^)0.9880.956--1.0200.449Preoperative comorbidities Previous abdominal surgery0.9960.722--1.3740.982 Diabetes mellitus1.1560.787--1.7000.460 Hypertension1.1280.891--1.4280.317Preoperative laboratory data Serum albumin \< 35 g/L1.6601.162--2.3720.0051.5441.068--2.2320.021 CRP ≥ 10 g/L1.3150.892--1.9380.167ASA ≥ 31.0470.834--1.3150.693Mode of surgical approach Laparoscopic0.6840.394--1.1880.178 OpenType of resection0.0670.025 Total gastrectomyReferenceReference Distal gastrectomy1.1830.932--1.5030.1671.2420.972--1.5880.083 Proximal gastrectomy1.5031.047--2.1570.0271.6131.117--2.3290.011Operation time1.0021.001--1.0040.0091.0031.001--1.0050.002Blood loss1.0001.000--1.0010.094Tumor site0.780 Cardia/fundusReference Body1.0540.811--1.3700.693 Pylorus/antrum0.9470.716--1.2520.701Tumor invasion (T3--4)1.2160.968--1.5270.093RLNs0.9910.979--1.0040.165Lymph node metastasis1.0440.832--1.3100.707LNR \> 0.051.2130.969--1.5170.091LODDS \> − 1.11.2190.975--1.5250.083pTNM stage (≥ III)1.0360.826--1.3000.757Lauren subtype0.952 IntestinalReference Diffuse0.8660.427--1.7540.689 Mixed0.9040.442--1.8480.782 Unknown0.9250.452--1.8940.832

Impact of RLN count on postoperative complications {#Sec9}
--------------------------------------------------

Of the 1487 patients, 435 (29.3%) developed complications: 74% (323 of 435) encountered a single complication, and 26% (112 of 435) encountered multiple complications. The details of patients with short-term complications based on the Clavien-Dindo classification are 15.5% for grade I, 9.2% for grade II, 4.0% for grade III, 0.3% for grade IV, and 0.2% for grade V. The rate of major complications (CDC grade ≥ III) was 4.5%. The median RLN count in this study was 24. So, we divided all patients into two groups based on the median RLN count. Univariate analyses showed no significant difference between RLN count and postoperative complications (both overall and stratified by CDC grade) (Table [3](#Tab3){ref-type="table"}). Table 3Univariate analyses of postoperative complications associated with RLN countCharacteristicsAllRLN count*P* value\< 25≥ 25Overall (*n*)4352481870.062Grade I (*n*)231132990.198 Fever \> 37.5 °C1448559 Emesis1568373 Pain301812 Abdominopelvic collection110 Pleural effusion440Grade II (*n*)13778590.366 Blood transfusions603822 Early postoperative bowel obstruction211 Gastroparesis251411 Liver function abnormalities110 Wound infection853 Pneumonia271512 Intra-abdominal infections20128 Urinary tract infection404 Enteritis312 Bacteremia1477Grade III (*n*)5932270.878 Anastomotic leakage23149 Lymphatic leakage835 Pancreatic fistula202 Biliary fistula101 Bleeding853 Abdominopelvic collection110 Pleural effusion954 Intra-abdominal abscess211 Wound disruption330 Delayed wound healing431 Gastroparesis101 Early postoperative bowel obstruction101 Splenic necrosis101Grade IV (*n*)5410.452 Heart failure110 Kidney failure110 Brain infarction101 MODS220Grade V (*n*)3211.000Grade ≥ III (*n*)6738290.562*RLNs* retrieved lymph nodes, *MODS* multiple organ dysfunction syndrome

Factors associated with RLN count {#Sec10}
---------------------------------

We further explored the potential factors associated with RLN count. Univariate analyses revealed that preoperative serum albumin, type of resection, tumor invasion, lymph node metastasis, and pTNM stage were associated with RLN count (*P* \< 0.05; Table [4](#Tab4){ref-type="table"}). Stratification by type of resection showed that RLN count in either distal gastrectomy or proximal gastrectomy was significantly lower than that in total gastrectomy. Multivariate analyses further indicated that type of resection, tumor invasion, and lymph node metastasis were still significantly associated with RLN count (*P* \< 0.05; Table [4](#Tab4){ref-type="table"}). Table 4Univariate and multivariate analyses of factors associated with RLN count ≥ 25CharacteristicsUnivariateMultivariateOR95% CI*P*OR95% CI*P*Age ≥ 700.8730.689--1.1050.259Gender Male1.0430.828--1.3120.723 FemaleBMI (kg/m^2^)0.9720.944--1.0020.064Preoperative comorbidities Previous abdominal surgery1.0300.768--1.3800.844 Diabetes mellitus0.9600.670--1.3750.822 Hypertension0.8520.685--1.0590.148Preoperative laboratory data Serum albumin \< 35 g/L1.4841.048--2.1020.026 CRP ≥ 10 g/L1.1950.827--1.7260.343ASA ≥ 30.8920.725--1.0980.282Mode of surgical approach Laparoscopic1.2820.808--2.0360.292 OpenType of resection\< 0.001\< 0.001 Total gastrectomyReferenceReference Distal gastrectomy0.6490.522--0.807\< 0.0010.7160.572--0.8960.004 Proximal gastrectomy0.3340.231--0.485\< 0.0010.3570.245--0.519\< 0.001Operation time1.0011.000--1.0030.086Blood loss1.0001.000--1.0010.482Tumor site0.304 Cardia/fundusReference Body0.9030.709--1.1480.404 Pylorus/antrum1.1190.869--1.4420.382Tumor invasion (T3--4)1.6131.310--1.987\< 0.0011.2991.010--1.6700.042Lymph node metastasis1.5851.286--1.952\< 0.0011.3041.018--1.6690.035pTNM stage (≥ III)1.5551.263--1.914\< 0.001Lauren subtype0.082 IntestinalReference Diffuse1.0400.536--2.0190.908 Mixed1.3880.709--2.7160.339 Unknown1.3280.677--2.6030.409*BMI* body mass index, *CRP* C-reactive protein, *ASA* American Society of Anesthesiologists, *RLNs* retrieved lymph nodes, *OR* odds ratio, *CI* confidence interval

Discussion {#Sec11}
==========

Nodal involvement significantly affected the prognosis of GC patients because it is the major root of tumor relapse after surgery \[[@CR14], [@CR15]\]. Thus, standardized lymph node dissection is the basic requirement for curative (R0) gastrectomy. Curative gastrectomy with D2 lymphadenectomy has been considered as the standard fashion for decades in Eastern Asia, especially in Japan \[[@CR16], [@CR17]\]. This procedure has been gradually accepted by Western countries in recent years \[[@CR18], [@CR19]\]. As for the RLN count, the 8th edition TNM classification for GC recommended dissecting at least 16 lymph nodes. Moreover, emerging evidence revealed the positive correlations between RLN count and overall survival of GC patients \[[@CR4], [@CR5], [@CR20]\]. By comparing RLN count to survival time, Okajima et al. suggested an optimal RLN count of ≥ 25 \[[@CR9]\]; Deng et al. proposed an optimal RLN count of ≥ 16 for lymph node-negative GC and \> 30 for lymph node-positive GC by stratum analysis of 7620 patients \[[@CR10]\]; Sano et al. reported that RLN count preferably achieved 30 or more by a multicenter study enrolling 25,411 patients \[[@CR20]\]. Additionally, LNR and LODDS were also reported to be associated with GC prognosis \[[@CR21]--[@CR23]\]. These above studies mainly focused on the relationship between RLN count and long-term prognosis. However, little is known about its effects on postoperative short-term complications.

In this study, we concentrated on the association between RLN count and short-term prognosis. Univariate analyses showed no significant difference between RLN count and postoperative complications (both overall and stratified by CDC grade). Therefore, more lymph nodes were encouraged to be dissected from the perspective of short-term prognosis.

Although curative gastrectomy with D2 lymphadenectomy is considered a pivotal strategy for advanced GC, there are international and institutional differences in the number of RLN count \[[@CR24], [@CR25]\]. Various factors were reported to influence the RLN count, including the confidence and enthusiasm of doctors (both surgeons and pathologists), surgical situation, and innate lymph node count in each patient \[[@CR7], [@CR9]\]. In our study, we concluded that RLN count was related to the type of resection, tumor invasion, and lymph node metastasis. Of note, RLN count was positively correlated with the lymph node metastasis rate, which underlined the importance of RLN count for accurate staging.

Actually, for a thorough pathological examination, RLNs should be individually divided from a complete tissue sample after surgery. Owing to much time and effort was required during this procedure, it has not been widely implemented clinically. Therefore, the examined lymph node count by pathologists might be lower than the dissected lymph node count. Multiple attempts have been conducted to improve the detection rate of lymph nodes \[[@CR26]--[@CR28]\]. Li et al. elucidated that the mean number of RLNs could be significantly elevated by injecting carbon nanoparticles before surgery compared with controls (38.33 vs 28.27) \[[@CR26]\]. Markl and colleagues reported a twofold lymph node pick up rate utilizing methylene blue staining than unstained groups (35 vs 17) \[[@CR27]\]. Several dye materials were also used to increase the number of lymph nodes dissected during surgery, such as fluorescent indocyanine green (ICG) and 5-aminolevulinic acid (5-ALA) \[[@CR29], [@CR30]\].

We acknowledge that this study had some potential limitations. First, it was a retrospective, single-center study, so the results might be flawed because of residual confounding factors. Second, the RLN count was closely related to the quality of surgeons and pathologists. The perioperative variables might differ in different doctors. Therefore, multicenter studies are needed to confirm our results.

Conclusions {#Sec12}
===========

In conclusion, the current study demonstrated that RLNs\\ count was not associated with postoperative short-term complications following gastrectomy of GC. Therefore, our analysis encouraged more lymph nodes to be dissected for accurate pathologic staging.

BMI

:   Body mass index

CRP

:   C-reactive protein

ASA

:   American Society of Anesthesiologists

RLNs

:   Retrieved lymph nodes

LNR

:   Lymph node ratio

LODDS

:   Log odds of positive lymph nodes

**Publisher's Note**

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Feng Sun, Song Liu and Peng Song contributed equally to this work.

The authors gratefully acknowledge all the investigators for their contributions to the trial.

FS worked on the study design, collected the data, and drafted the manuscript. SL contributed to the study design and data collection. PS was involved in the data collection and extraction. CZ helped collect the data. WG was involved in the study design and data extraction. MW revised the manuscript. All authors have read and approved the final manuscript.

There is no funding supporting this work.

Access to the data and the calculation method can be obtained from the authors by email (medsunfeng\@163.com).

This retrospective study was approved by the ethics committee of Nanjing Drum Tower Hospital, Medical School of Nanjing University. Due to the retrospective nature, the requirement for informed consent was waived by the IRBs from Nanjing Drum Tower Hospital, Medical School of Nanjing University.

Not applicable.

The authors declare that they have no competing interests.


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    $qb->select(array('uid'))
        ->from('person', 't');
    $query = $qb->getQuery();

    $result = $query->getResult();
    echo $result;
?>

When I visit myTestPage.php, I get the following error message:

Fatal error: Uncaught exception 'Doctrine\ORM\Query\QueryException'
  with message '[Semantical Error] line 0, col 24 near 'person':
  Error: Class 'person' is not defined.' in
  C:\wamp\www\Doctrine\Doctrine\ORM\Query\QueryException.php on line 47

The problem seems to be that Doctrine can't find person.php, but how can I solve this?

A:

I don't exactly know what the "re1_chercheur" means, but when I tried your code, it complained about person not being defined, so i included that and it worked.
Of course, this should be dealt with by using an autoloader of some sort, but I think doctrine has some solution for that also. I haven't been using their autoloader, because I have my own which uses the PSR compliant autoloading.
Also in your select, if you want just the "uid", use "t.uid". "t" is the alias of the person class, so in other places in the query, you'll be using "t" to get to it's properties (you could do a ->where("t.uid = someNumber")). If you want the whole object use select("t");
I found the doctrine documentation quite helpful, just make sure you go in the order it is laid out, and you'll get the hang of it in no time.
I know this is not an exact answer, but maybe it points you into the right direction.


The bradykinin receptor--a putative receptor-operated channel in PC12 cells: studies of neurotransmitter release and inositol phosphate accumulation.
Bradykinin (BK) induced [3H]norepinephrine [( 3H]NE) release and phosphatidylinositol turnover were investigated in PC12 cells. Induction of [3H]NE release by BK is mediated by activation of BK-B2-receptors, as determined using type specific BK receptor antagonists. BK induces [3H]NE release with a half maximal effective concentration of 30 +/- 0.5 nM, and reaches maximal net fractional release of 9.0 +/- 1% with 200 nM BK. The BK-induced release is Ca2+ dependent, reaching maximal release at 1.0 mM Ca2+, is pertussis toxin insensitive (1 microgram/ml), slightly increased by a dibutyryl cAMP (1 mM) and not affected by inhibitors of the cyclooxygenase or lipoxygenase pathways. Voltage-sensitive Ca2+ channel blockers, verapamil (10 microM), nifedipine (10 microM), and omega-conotoxin (CgTx 10 nM), do not block the BK-induced release. However, a considerable inhibitory effect was obtained by divalent cations Co2+ (ED50 = 0.2 mM) and Ni2+ (ED50(2)+ = 1 mM). These results indicate the involvement of a Ca2+ channel in the BK-mediated release which is different from the L- or N-type voltage sensitive calcium channels. Whereas [Ca2+]ex is essential for the BK-induction of catecholamine release, the rise in level of InsP's induced by BK in the presence or in the absence of [Ca2+]ex is similar up to concentration of 1 microM. This indicates that the rise in InsP's induced by BK is not sufficient to cause neurotransmitter release. Moreover, subsequent addition of Ca2+ to BK-stimulated cells in Ca(2+)-free medium yields no release. Hence, no activity triggered by BK alone could be further stimulated by Ca2+ for induction of release.(ABSTRACT TRUNCATED AT 250 WORDS)


NIKE - Featuring the latest and greatest performance technology such as advanced cushioning and ultra-durable materials, there’s a shoe for you right here. Enjoy unbeatable comfort and performance when you need it, where you need it. Reach for any goal you choose—if the going gets tough, then put on a pair of Nike shoes and just do it.

Details

Alphabounce EM Shoes

A neutral running shoe with breathable, lightweight design.

Make the off-season count. Keep your cross-training focus in these men's running shoes.Designed with an engineered mesh upper, the shoes feature sock-like construction for breathable comfort during long workouts. A Bounce midsole powers you forward with flexible cushioning, while seamless overlays on the upper maintain a locked-down fit. The neoprene tongue and heel adapt to your ankle's natural movement.


Thermodynamic model of nonequilibrium phase transitions.
Within the scope of a thermodynamic description using the maximum entropy production principle, transitions from one nonequilibrium (kinetic) regime to another are considered. It is shown that in the case when power-law dependencies of thermodynamic flux on force are similar for two regimes, only a transition accompanied by a positive jump of thermodynamic flux is possible between them. It is found that the difference in powers of the dependencies of thermodynamic fluxes on forces results in a number of interesting nonequilibrium transitions between kinetic regimes, including the reentrant one with a negative jump of thermodynamic flux.


In recent years, vehicles such as automobiles have been equipped with many vehicle control devices, i.e., vehicle control devices that electronically control various pieces of in-vehicle equipment, such as an engine and a brake, and vehicle control devices that control pieces of equipment, such as meters, that display various vehicle states, including a vehicle control device that controls a navigation system. Additionally, in the vehicle, a vehicle network is formed by electrically connecting those vehicle control devices together by means of communication lines, and various pieces of data are transmitted and received between the vehicle control devices through this vehicle network. On the other hand, in the thus formed vehicle network, each vehicle control device connected to the vehicle network serves to control various pieces of in-vehicle equipment, such as an engine and a brake, that are mounted in the vehicle, and hence is required to have significantly-high security.
Therefore, recently, the development of an authentication system to verify the correctness of communication targets or of communication data between the vehicle control devices connected to the vehicle network has been advanced. In this kind of system, communication with a communication target is started on condition that authentication has been established.
Additionally, for example, a data distribution system described in Patent Document 1 has been known as a technique that increases the security of such a specific network. This data distribution system communicates dummy data that is a dummy representation of normal data between a transmitting terminal and a receiving terminal, besides the normal data. The receiving terminal determines whether received data is dummy data or normal data. As a result, it is difficult to identify normal data even if data transmitted to the network is illegally obtained.


Sports

The coaching carousel has come to a stop, at least for the 2013 offseason. All eight teams that fired their head coach following the season have found a new one. So, let’s put together a power rankings of how each squad did.

1. Kansas City – The Chiefs wasted no time in going out and getting the biggest fish in the pond, Andy Reid. It’s tough to see what the appeal was for Reid to go to Kansas City, a team coming off a two-win season that has no reliable -- or even passable -- quarterback in place, but somehow the Chiefs convinced him to come. Reid gives the Chiefs instant credibility and changes the dynamic of the AFC West.

If the Chiefs can get the quarterback position figured out, an area where Reid has had plenty of success in the past, they could show significant improvement next season, which is why the Chiefs landing Reid was the biggest coup of the offseason.

2. Philadelphia – It took a while to unfold, but the Eagles were finally able to convince Chip Kelly to leave Oregon and come to the NFL. Kelly is a tireless worker and one of the most innovative offensive minds in the sport, so he’s a perfect fit for the NFL. He’ll have to find a quarterback to run his system, and he’ll have to tweak his system a bit to adapt to the NFL, but Kelly immediately becomes one of the smartest head coaches in the league, and the Eagles should feel optimistic about their future with him as their coach.

3. Arizona – The Cardinals may have missed on the big names like Reid, but they did manage to hire Bruce Arians, who had one of the most impressive coaching performances of the 2012 season as interim coach of the Colts. Not only did Arians step into an impossible situation with Chuck Pagano forced to take a leave of absence to receive cancer treatment, but he also led the Colts to a 9-3 record while serving as the interim coach. If that wasn’t enough, Arians also has nine years of experience being an NFL offensive coordinator, making him a qualified candidate and a great pick to be Arizona’s head coach.

4. San Diego – The Chargers waited too long to fire Norv Turner and then waited out the end of Denver’s season, but they were rewarded in the end with the hiring of Mike McCoy. Not only did they steal the offensive coordinator of one of their biggest rivals, but they also hired one of the top offensive coordinators in the game and arguably the best candidate to make the transition from coordinator to head coach. McCoy should help breathe new life into San Diego’s offense, and possibly help revive the floundering career of quarterback Phillip Rivers, which is exactly what they need if they expect to compete with the Broncos in the AFC West.

5. Buffalo – Doug Marrone isn’t the big name that Bills fans were hoping for, but with a handful of teams with a head-coaching vacancy wanting to talk to the former Syracuse head coach, Marrone was a wanted commodity, and the fact that he chose the Bills does mean something. He comes with a high praise and a glowing recommendation from both New Orleans coach Sean Payton and New Orleans general manager Mickey Loomis, both of whom worked with Marrone when he was the offensive coordinator of the Saints from 2006 to 2008. Marrone is young, a straight shooter, and has a keen offensive mind. He’s a better candidate than most Bills fans realize, and he should give the franchise a much-needed culture change.

6. Chicago – Marc Trestman is arguably the second most qualified coach on this list (behind Reid), but he drops down significantly because he hasn’t coached in the NFL in almost a decade, and a lot has changed since he’s been away. Trestman has spent the last five years as a head coach in the CFL, so being a head coach won’t be an issue, but readjusting to the NFL could be. That being said, Trestman has a long history of working with quarterbacks, and with the Bears having a talented, yet underachieving, quarterback in place in Jay Cutler, Trestman could end up being a good pick to help both Cutler and the Bears get to the next level.

7. Jacksonville – The Jaguars took a risk when they hired a new coach for the second consecutive season, and they’re taking another risk by hiring a coach as young and inexperienced as Gus Bradley. He is a young and highly regarded defensive coach, but he has spent just seven seasons as an assistant in the NFL. Bradley has done a great job turning Seattle’s defense around, and he may be a rising star in the coaching ranks, but whether he’s ready to be an NFL head coach is a different issue, which gives him a lot to prove.

8. Cleveland – This was the job no one really seemed to want, and in the end the Browns settled for Rob Chudzinski. In the four years that Chudzinski has spent as an offensive coordinator in the NFL, he’s had good success, both with the Browns and in the past two seasons with the Panthers. He’s a young guy and a bright offensive coach, but will he be ready to take on the duties of an NFL head coach, specifically the steep challenges that he’ll face in Cleveland? Chudzinski may be destined to be an NFL head coach, but at this point in his career and at this location, he may be in over his head.


<?php

namespace Butschster\Tests\MetaTags;

use Butschster\Tests\TestCase;

class RobotsMetaTagsTest extends TestCase
{
    function test_robots_from_string_can_be_set()
    {
        $meta = $this->makeMetaTags()
            ->setRobots('noindex');

        $this->assertHtmlableEquals(
            '<meta name="robots" content="noindex">',
            $meta->getRobots()
        );
    }
    function test_robots_from_string_can_be_null()
    {
        $this->assertHtmlableEquals(
            '<meta name="robots" content="">',
            $this->makeMetaTags()->setRobots(null)->getRobots()
        );
    }

    function test_set_robots_method_should_be_fluent()
    {
        $meta = $this->makeMetaTags();

        $this->assertEquals($meta, $meta->setRobots('noindex'));
    }

    function test_robots_should_be_null_if_not_set()
    {
        $meta = $this->makeMetaTags();

        $this->assertNull($meta->getRobots());
    }

    function test_robots_string_should_be_cleaned()
    {
        $meta = $this->makeMetaTags()
            ->setRobots('
noindex
');

        $this->assertHtmlableEquals(
            '<meta name="robots" content="noindex">',
            $meta->getRobots()
        );
    }
}


The world’s oldest man has been forced to cancel his 112th birthday celebrations because of the coronavirus outbreak.

Bob Weighton, from Alton, Hampshire, took up the title of the oldest man in the world last month after the death of the previous holder, Chitetsu Watanabe of Japan, and celebrates his birthday on Sunday March 29.

Mr Weighton, who also lived through the Spanish flu pandemic which swept around the globe in 1918 when he was 10 years old, said his celebrations are a “dead loss”.

“Everything is cancelled, no visitors, no celebration," he told the Press Association.

Last year, the former teacher and engineer celebrated with his many friends at his retirement flat but this year the supercentenarian – someone aged 110 and older – is under lockdown like the rest of the country.

Bob Weighton Credit: Magnus Weighton/PA

On the Spanish flu pandemic which killed between 50 and 100 million people, Mr Weighton said he "only read about it in history books when I got older".

He added: “Actually I wasn’t aware there was a Spanish flu around because none of my brothers and sisters or people I knew were affected.

“I am sure they were, but a child’s world is not an adult’s world, a child doesn’t read the newspapers and there was no radio in those days so you didn’t get news in the sense you get it thrown at you in all directions nowadays.”

Mr Weighton said that now the “world is in a bit of a mess” with coronavirus and it worries him because “nobody knows what is going to happen”.

He added that, unlike the two World Wars he lived through, the challenge of Covid-19 is the unknown elements of battling the virus.

He said: “In the Second World War you knew what you had to do, you might fail but the objectives were clear as Churchill rallied the country behind him, ‘We will fight on the beaches’, etc etc.

“We knew exactly what we had to do. That was an objective that you could possibly reach, but nobody knows how we are going to defeat the virus.”

Bob Weighton teaching in 1934 Credit: Family handout/PA

He said the impact on him of self-isolation was that he had become more dependent on the Brendoncare home where he lives, particularly for meals and from the assistant who helps him clean and lift heavier objects.

He said: “It means that I have to be more self-sufficient, do my own cooking, cleaning, read the books that I haven’t read.

“I am less capable of doing things for myself than I was 10 years ago – I can’t lift the weights, I can’t move as fast, I can’t even dress myself properly.

“I depend very much on other people these days.”

Mr Weighton said he had no secret to his longevity, adding: “I never intended to be this old. When you are young, you don’t think about what is going to happen when you’re old, you’re self-engaged, all you think about is the here and now.”

But he did say that his wide general interests from reading to constructing model windmills keep him active and young.

“Those are things you do either naturally or don’t do. People who complain are those who don’t explore things that they might do themselves,” he said.

A young Bob Weighton Credit: Family handout/PA

Mr Weighton added that he has turned down the traditional birthday greeting from the Queen.

“I won’t be getting one because I don’t want one,” he said.

“I had about 10 and I don’t see why I should require the Queen to keep giving me cards. It costs the taxpayer not her something, so I have selected one in which she is smiling, looking happy and contented and that’s the one I like and I keep that.”

Joan Hocquard also turned 112 on Sunday. Credit: Oldest in Britain

Mr Weighton was born in Hull on March 29, 1908, which, by coincidence, is the same day as Britain’s oldest woman, Joan Hocquard, from Poole, Dorset, and also the birthday of Alf Smith, from St Madoes in Perthshire, Scotland, who shared the title of Britain’s oldest man until his death last year.

Mr Weighton said: “I don’t know Joan but I would like to send her my best wishes for her birthday.”

The father-of-three – one of seven himself – has 10 grandchildren and 25 great-grandchildren.


Ultrafast Dynamics at Water Interfaces Studied by Vibrational Sum Frequency Generation Spectroscopy.
We present an overview of studies on the ultrafast dynamics of water at aqueous interfaces carried out by time-resolved vibrational sum frequency generation (VSFG) spectroscopies. This research field has been growing rapidly, stimulated by technical developments achieved recently. In this review, first, the principles and instrumentations are described for conventional VSFG, heterodyne-detected VSFG, and various IR-pump/VSFG-probe techniques, namely, time-resolved conventional VSFG, time-resolved heterodyne-detected VSFG, and their extension to two-dimensional spectroscopy. Second, the applications of these time-resolved VSFG techniques to the study of the femtosecond vibrational dynamics of water at various interfaces are discussed, in the order of silica/water, charged monolayer/water, and the air/water interfaces. These studies demonstrate that there exists water dynamics specific to the interfaces and that time-resolved VSFG spectroscopies can unambiguously detect such unique dynamics in an interface-selective manner. In particular, the most recent time-resolved heterodyne-detected VSFG and two-dimensional heterodyne-detected VSFG unveil the inhomogeneity of the hydrogen bond and relevant vibrational dynamics of interfacial water through unambiguous observation of hole-burning in the OH stretch band, as well as the subsequent spectral diffusion in the femtosecond time region. These time-resolved VSFG studies have also left several issues for discussion. We describe not only the obtained conclusive physical insights into interfacial water dynamics but also the points left unclear or controversial. A new type of experiment that utilizes UV excitation is also described briefly. Lastly, the summary and some future perspectives of time-resolved VSFG spectroscopies are given.


Q:

Contingent sentences can always be true

I have a question about contingent sentences. To my knowledge, contingent sentences are sentences that are neither tautologies nor contradictions.
In a textbook I read that a sentence might always be true and still be contingent.
The example given was as follows: If there never were a time when the universe contained fewer than seven things, it follows that the sentence "At least seven things exist" would always be true. Yet the sentence is contingent; its truth isn't a matter of logic. There is no contradiction in considering a possible world in which there are less than seven things.
Could someone please explain why this is the case? As well as explain the example to me?

A:

In mathematical logic - the discipline of logic that has interested computer scientists the most - there is a difference between proof-theoretic truth and model-theoretic truth.
Beyond metaphor (of which we are by no means innocent), neither has anything to do with reality, experienced or imagined, and with the idea of truth that is dealt with by empirical scientists, natural philosophers and historians, to which you allude in your question.
Contingent is, to us, another name for a sentence that is satisfiable, but not a tautology. This has to do with its truth equivalence being dependent on the axioms and rules of inference available (proof-theoretic aspect), or on the valuation of its symbols (model-theoretic aspect).
Gödel showed us that these two aspects do not necessarily go together very well, though. Caution is advised.


// Copyright 2016 The etcd Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package main

import (
	"flag"
	"fmt"
	"log"
	"math/rand"
	"os"
	"strings"
	"sync"
	"time"

	"golang.org/x/net/context"
	"google.golang.org/grpc"
	"google.golang.org/grpc/codes"

	"github.com/coreos/etcd/clientv3"
	"github.com/coreos/etcd/clientv3/concurrency"
)

func main() {
	log.SetFlags(log.Lmicroseconds)

	endpointStr := flag.String("endpoints", "localhost:2379", "endpoints of etcd cluster")
	mode := flag.String("mode", "lock-racer", "test mode (election, lock-racer, lease-renewer)")
	round := flag.Int("rounds", 100, "number of rounds to run")
	flag.Parse()
	eps := strings.Split(*endpointStr, ",")

	switch *mode {
	case "election":
		runElection(eps, *round)
	case "lock-racer":
		runRacer(eps, *round)
	case "lease-renewer":
		runLeaseRenewer(eps)
	default:
		fmt.Fprintf(os.Stderr, "unsupported mode %v\n", *mode)
	}
}

func runElection(eps []string, rounds int) {
	rcs := make([]roundClient, 15)
	validatec, releasec := make(chan struct{}, len(rcs)), make(chan struct{}, len(rcs))
	for range rcs {
		releasec <- struct{}{}
	}

	for i := range rcs {
		v := fmt.Sprintf("%d", i)
		observedLeader := ""
		validateWaiters := 0

		rcs[i].c = randClient(eps)
		var (
			s   *concurrency.Session
			err error
		)
		for {
			s, err = concurrency.NewSession(rcs[i].c)
			if err == nil {
				break
			}
		}
		e := concurrency.NewElection(s, "electors")

		rcs[i].acquire = func() error {
			<-releasec
			ctx, cancel := context.WithCancel(context.Background())
			go func() {
				if ol, ok := <-e.Observe(ctx); ok {
					observedLeader = string(ol.Kvs[0].Value)
					if observedLeader != v {
						cancel()
					}
				}
			}()
			err = e.Campaign(ctx, v)
			if err == nil {
				observedLeader = v
			}
			if observedLeader == v {
				validateWaiters = len(rcs)
			}
			select {
			case <-ctx.Done():
				return nil
			default:
				cancel()
				return err
			}
		}
		rcs[i].validate = func() error {
			if l, err := e.Leader(context.TODO()); err == nil && l != observedLeader {
				return fmt.Errorf("expected leader %q, got %q", observedLeader, l)
			}
			validatec <- struct{}{}
			return nil
		}
		rcs[i].release = func() error {
			for validateWaiters > 0 {
				select {
				case <-validatec:
					validateWaiters--
				default:
					return fmt.Errorf("waiting on followers")
				}
			}
			if err := e.Resign(context.TODO()); err != nil {
				return err
			}
			if observedLeader == v {
				for range rcs {
					releasec <- struct{}{}
				}
			}
			observedLeader = ""
			return nil
		}
	}
	doRounds(rcs, rounds)
}

func runLeaseRenewer(eps []string) {
	c := randClient(eps)
	ctx := context.Background()

	for {
		var (
			l   *clientv3.LeaseGrantResponse
			lk  *clientv3.LeaseKeepAliveResponse
			err error
		)
		for {
			l, err = c.Lease.Grant(ctx, 5)
			if err == nil {
				break
			}
		}
		expire := time.Now().Add(time.Duration(l.TTL-1) * time.Second)

		for {
			lk, err = c.Lease.KeepAliveOnce(ctx, l.ID)
			if grpc.Code(err) == codes.NotFound {
				if time.Since(expire) < 0 {
					log.Printf("bad renew! exceeded: %v", time.Since(expire))
					for {
						lk, err = c.Lease.KeepAliveOnce(ctx, l.ID)
						fmt.Println(lk, err)
						time.Sleep(time.Second)
					}
				}
				log.Printf("lost lease %d, expire: %v\n", l.ID, expire)
				break
			}
			if err != nil {
				continue
			}
			expire = time.Now().Add(time.Duration(lk.TTL-1) * time.Second)
			log.Printf("renewed lease %d, expire: %v\n", lk.ID, expire)
			time.Sleep(time.Duration(lk.TTL-2) * time.Second)
		}
	}
}

func runRacer(eps []string, round int) {
	rcs := make([]roundClient, 15)
	ctx := context.Background()
	cnt := 0
	for i := range rcs {
		rcs[i].c = randClient(eps)
		var (
			s   *concurrency.Session
			err error
		)
		for {
			s, err = concurrency.NewSession(rcs[i].c)
			if err == nil {
				break
			}
		}
		m := concurrency.NewMutex(s, "racers")
		rcs[i].acquire = func() error { return m.Lock(ctx) }
		rcs[i].validate = func() error {
			if cnt++; cnt != 1 {
				return fmt.Errorf("bad lock; count: %d", cnt)
			}
			return nil
		}
		rcs[i].release = func() error {
			if err := m.Unlock(ctx); err != nil {
				return err
			}
			cnt = 0
			return nil
		}
	}
	doRounds(rcs, round)
}

func randClient(eps []string) *clientv3.Client {
	neps := make([]string, len(eps))
	copy(neps, eps)

	for i := range neps {
		j := rand.Intn(i + 1)
		neps[i], neps[j] = neps[j], neps[i]
	}

	c, err := clientv3.New(clientv3.Config{
		Endpoints:   eps,
		DialTimeout: 5 * time.Second,
	})
	if err != nil {
		log.Fatal(err)
	}
	return c
}

type roundClient struct {
	c        *clientv3.Client
	progress int
	acquire  func() error
	validate func() error
	release  func() error
}

func doRounds(rcs []roundClient, rounds int) {
	var mu sync.Mutex
	var wg sync.WaitGroup

	wg.Add(len(rcs))
	finished := make(chan struct{}, 0)
	for i := range rcs {
		go func(rc *roundClient) {
			defer wg.Done()
			for rc.progress < rounds {
				for rc.acquire() != nil { /* spin */
				}

				mu.Lock()
				if err := rc.validate(); err != nil {
					log.Fatal(err)
				}
				mu.Unlock()

				time.Sleep(10 * time.Millisecond)
				rc.progress++
				finished <- struct{}{}

				mu.Lock()
				for rc.release() != nil {
					mu.Unlock()
					mu.Lock()
				}
				mu.Unlock()
			}
		}(&rcs[i])
	}

	start := time.Now()
	for i := 1; i < len(rcs)*rounds+1; i++ {
		select {
		case <-finished:
			if i%100 == 0 {
				fmt.Printf("finished %d, took %v\n", i, time.Since(start))
				start = time.Now()
			}
		case <-time.After(time.Minute):
			log.Panic("no progress after 1 minute!")
		}
	}

	wg.Wait()
	for _, rc := range rcs {
		rc.c.Close()
	}
}


Obama administration delays penalties for Obamacare sign-up

Health and Human Services Secretary Kathleen Sebelius arrives in the Rose Garden of the White House in Washington for and event with President Barack Obama on the initial rollout of the health care overhaul. As the public face of President Barack Obama’s signature health care program, Sebelius has become the target for attacks over its botched rollout. Republicans want her to resign and even some Democrats - while not mentioning her name - say someone needs to be fired.

President Barack Obama and administration officials are not giving up on the Affordable Care Act despite its rocky rollout that has furthered public apprehension about the comprehensive health care reform law, but they are giving up on one thing: the law’s mandate deadline for insurance coverage.

Health and Human Services officials said late Monday Americans without health insurance would have until March 31, rather than Feb. 15, to enroll in coverage before incurring a penalty. The enrollment mandate is meant to encourage young, healthy applicants into the insurance markets to lower the premium costs for the broader range of enrollees. It is one of of the law’s most controversial aspects, one loathed by conservatives who see it as government overreach.

But after the failed debut of healthcare.gov, the website intended to be a one-stop shop for comparing policies and signing up for coverage, and the subsequent political beating the administration has taken, the administration announced the deadline change.

In guidance announced Monday night, HHS “has determined that it would be unfair to require individuals in this situation to make a [penalty] payment.”

Advertisement

White House spokesman Jay Carney recently hinted at a potential delay after he noted there was a “disconnect” between the website glitches and looming penalties. “There’s no question that there’s a disconnect between open enrollment and the individual responsibility timeframes in the first year only,” Carney said at an Oct. 21 press briefing. “And those are going to be addressed.”

Republicans have relished the political ramifications of the website failings, using it as an example to justify their opposition to Obamacare. Some lawmakers, such as Sen. Marco Rubio, R-Fla., filed legislation that would require a delay in the individual mandate until all the technical issues are addressed. But Senate Majority Leader Harry Reid and other top Democrats refuse to move such bills without White House approval, something not expected.

But Republicans, whose attempt to defund Obamacare led to an unpopular 16-game federal shutdown, are trying to regain the edge on the unpopular law by highlighting each one of the administration’s health care fumbles.


Winnipeg Jets v San Jose Sharks

Nick Lust

Andrew Desjardins #10 of the San Jose Sharks crashes the net against Al Montoya #35 andTobias Enstrom #39 of the Winnipeg Jets during an NHL game on March 27, 2014 at SAP Center in San Jose, California.

Andrew Desjardins #10 of the San Jose Sharks crashes the net against Al Montoya #35 andTobias Enstrom #39 of the Winnipeg Jets during an NHL game on March 27, 2014 at SAP Center in San Jose, California.

Winnipeg Jets v San Jose Sharks

Ezra Shaw

Tobias Enstrom #39 of the Winnipeg Jets scores the game-winning goal with a shot that got past Justin Braun #61 and goalie Antti Niemi #31 of the San Jose Sharks at SAP Center on March 27, 2014 in San Jose, California.

Tobias Enstrom #39 of the Winnipeg Jets scores the game-winning goal with a shot that got past Justin Braun #61 and goalie Antti Niemi #31 of the San Jose Sharks at SAP Center on March 27, 2014 in San Jose, California.

Winnipeg Jets v San Jose Sharks

Nick Lust

Joe Thornton #19 of the San Jose Sharks battles for the puck in his 1200th NHL game against Bryan Little #18 of the Winnipeg Jets during an NHL game on March 27, 2014 at SAP Center in San Jose, California.

Joe Thornton #19 of the San Jose Sharks battles for the puck in his 1200th NHL game against Bryan Little #18 of the Winnipeg Jets during an NHL game on March 27, 2014 at SAP Center in San Jose, California.


With consumers using their computers more-and-more for heavy duty on-line applications, the need for computer data centers has increased greatly. Data centers are centralized computing facilities that include hundreds, thousands, or even hundreds of thousands of computers, often arranged into numerous computer racks. Data centers are extremely important to modern computing and are also extremely expensive to build and operate.
Expenses for building data centers include land acquisition and standard building costs for the facility. In addition, thousands of computers and ancillary equipment must be purchased and installed. And electrical and mechanical equipment is needed to power and cool the equipment.
Operation of a data center is expensive because fast computers are needed and fast computers require electricity. As an unfortunate corollary, fast computers turn that electricity into heat, requiring more electricity to eliminate the heat. For example, many buildings use chillers, condensers, evaporators and other energy-consuming devices to cool a facility. And such devices require fans, pumps, and other ancillary electrically-powered equipment.


Q:

Spring5.0.1 VelocityEngineFactoryBean

Multiple annotations found at this line:
    - Class 'org.springframework.ui.velocity.VelocityEngineFactoryBean' not found
    - Class 'org.springframework.ui.velocity.VelocityEngineFactoryBean' not found [config set: MyApp/web-
     context]
    <bean id="velocityEngine" class="org.springframework.ui.velocity.VelocityEngineFactoryBean">
  <property name="velocityProperties">
     <value>
      resource.loader=class
      class.resource.loader.class=org.apache.velocity.runtime.resource.loader.ClasspathResourceLoader
     </value>
  </property>
</bean>

A:

Spring has marked Velocity package org.springframework.ui.velocity as deprecated in Spring 4.3 and removed it completely in Spring 5.0.1 (according to Jürgen Höller, it's because Velocity Framework "dates back to 2010").
Source: https://jira.spring.io/browse/SPR-13795.
However, you can still use Velocity 1.7 in Spring 5.0.x Framework.
Just follow the answer of @bekce in this thread.


Factors contributing to job satisfaction following rehabilitation for musculoskeletal impairments.
The study investigates whether changing jobs is related to work-related well-being of people with musculoskeletal impairments. In order to assess this relationship subjects who began new jobs after rehabilitation (N=52) were compared with subjects who returned to their former employment (N=63). Work-related well-being was measured by means of the scales "job satisfaction" and "need to recover after work." After controlling for individual characteristics (gender, age, working hours per week, and pain complaints) and job characteristics (job demands and decision latitude), job satisfaction could be predicted by job change. Recovery need after work was predicted by pain complaints, job demands, and decision latitude, but not by job change.


Hannah Horvath, will you be my BFF?

The second season of the HBO hit show Girls is barely off the ground and writer/executive producer/director/actress Lena Dunham is already been raked over the coals for her creative decisions for this season.

Girls, the brainchild of Dunham and comedy-gem maker Judd Apatow, has been widely written about since its debut last year. The premise of the show revolves around four white and seemingly wealthy 20-something women living in New York City.

The first season of Girls was widely criticized for the lack of racial diversity in the casting. Dunham stated it was unintentional and agreed that the casting choices were not reflective of the racially and culturally diverse New York City. So, in the second season African American actor/comedian Donald Glover was cast as Hannah Horvath (Dunham)’s new beau and this was met with mixed reviews. Most critics claimed that by casting Glover in a main role she was using him as the “token” minority in an attempt to make the show appear more diverse.

“… I really wrote the show from a gut-level place, and each character was a piece of me or based on someone close to me. And only later did I realize that it was four white girls. As much as I can say it was an accident, it was only later as the criticism came out, I thought, ‘I hear this and I want to respond to it.’ And this is a hard issue to speak to because all I want to do is sound sensitive and not say anything that will horrify anyone or make them feel more isolated, but I did write something that was super-specific to my experience, and I always want to avoid rendering an experience I can’t speak to accurately.” (Shalomlife.com)

Dunham stated that the decision to cast Glover was made before critics lambasted the casting of the first season and was due more to the fact he’s a brilliant comedian than about him being black. In my opinion critics claiming that Glover’s whole role was written only to add colour to the cast greatly diminish how well written and smart the character of Sandy the hot Republican (Glover) was in the storyline of Girls.

However, Dunham has received the most amount of criticism over her body. She has the audacity to be naked and sexual AND not look how everyone expects actresses to look naked. She is not afraid to act out her own sex scenes and own her body.

Personally I like seeing Dunham naked. She is not fat. She is completely average. She looks like a lot of women. She realistically represents a lot of women’s body types. So can we stop talking about how she is a grotesque exhibitionist? What ground is she breaking here? That slightly chubby women are sexual and can get boyfriends?

I hate to pop your bubble, but chubby and fat women have lovers and boyfriends and husbands and anything else they want. Sex isn’t just a club for the pretty skinny people. The more we build up Dunham’s average body to something obscene the more we are reinforcing that all women should look a certain way or else they are unworthy of love and success.

There are parts of the show and the writing which are problematic. There is a lack of diversity (hey – why don’t you cast an actual fat person in the show?), white middle class privilege is never accurately addressed, and no one seems to really work or really struggle. However, Dunham is attempting to address some very real issues a lot of women face in their lives (abortion, STDs, career, money, independence, body issues, emotional eating, and sexuality) and for that she should be commended.

I think most the appeal of Girls lays in its reliability within the 20-something demographic. And while I disagree with the women who are all, OMG THAT IS SOOOOOO MY LIFE (chances are your life is NOT like the show at all that because you probably have to work and junk), I believe Dunham does a good job of appealing and connecting to young women in a real way. Chances are most of us have had an “Adam” (Hannah’s emotionally broken love interest in the first season) who treats your heart like it is “monkey meat” and makes crazy. I know I have.

Despite the fact Dunham comes from a wealthy background and has majorly successful and well-connected parents I just can’t bring myself to not support a woman writing, producing, and starring in a mainstream TV show.

The mission of Girls Rock Camps is to build girls’ self-esteem through creative expression while encouraging them to believe in and assert their own power, agency, and build meaningful connections with each other.

Copyright Disclaimer

Unauthorized use of this material without express permission is prohibited. Excerpts and links may be used, provided that full and clear credit is given to post authors and Gender Focus with appropriate and specific direction to the original content.


Q:

Inject value at runtime

I have repository classes that require runtime values taken from Thread.CurrentPrincipal (i.e. authorization claims) in combination with regular singleton classes.
Given
public class MyRepository : IMyRepository
{
    private readonly DependencyClass _dependency;
    private readonly string claim;

    protected MyRepository(DependencyClass _dependency, string claim)
    {
        //...

When registering the repository, how can the claim be injected? e.g.
unity.RegisterType<IMyRepository, MyRepository>(new HierarchicalLifetimeManager());
unity.RegisterType<DependencyClass>(new ContainerControlledLifetimeManager());

InjectionConstructor seems to match the constructor parameters and therefore causes a runtime error. Still I'd prefer constructor injection, I'm just not sure how do that.

A:

I have repository classes that require runtime values

Your DI container should build up object graph that contain injectables/components; the classes that contain your application's logic. Runtime data should not be injected into a component's constructor, because that will complicate constructing, building and verifying the object graphs.
Instead, runtime data should be passed through the object graph using method calls. A general solution for this kind of contextual runtime data is to have an abstraction that provides this contextual data to its consumers.
In your case for instance, an IClaimsContext abstraction does the trick:
public interface IClaimsContext {
    string CurrentClaim { get; }
}

Using this abstraction, it is trivial to create an implementation that reads the claims from the Thread.CurrentPrincipal as you can see here:
public sealed class ThreadClaimsContext : IClaimsContext {
    public string CurrentClaim {
        get { return Thread.CurrentPrincipal... /* get claims here */; }
    }
}

Since this implementation contains no state, it can be registered as singleton without any problem:
unity.RegisterInstance<IClaimsContext>(new ThreadClaimsContext());

Now your MyRepository can simply depend on IClaimsContext instead of a string claims.


---
abstract: 'We study theoretically the dynamics of an “xxz” spin necklace coupled to a conduction electron sea, a model system for a nanostructure in a dissipative environment. We extract the long-time behavior via a mapping to a multichannel Coulomb gas problem followed by a scaling analysis. The strong quantum fluctuations of the necklace cause a nontrivial dependence of couplings on system size which we extract via an analysis involving the “boundary condition changing operator”, and confirm via a detailed numerical evaluation of one case.'
address: |
    $^{1}$Center for Materials Theory, Department of Physics & Astronomy, Rutgers University,\
    136 Frelinghuysen Road, Piscataway, NJ 08854.\
    $^{2}$ Department of Physics, Columbia University, 538 W 120th St, NY, NY 10027.
author:
- 'N. Shah$^{1}$ and A. J. Millis$^{2}$'
title: 'Dissipative dynamics of an extended magnetic nanostructure : Spin necklace in a metallic environment'
---

[2]{}

The dissipative dynamics of a magnetic nanostructure is important from both technological and fundamental points of view. For example, magnetic recording involves the polarization of small domains, whose stability over long times is crucial. Tunnelling of isolated magnetic particles has been extensively studied[@Chudnovsky][@Gunther]. We shall be interested here in the new physics brought by coupling to a conduction electron bath. There are two effects. Exchange of spin between the conduction electron system and the nanostructure changes the magnetic state of the nanostructure, leading effectively to a tunneling process. On the other hand, dissipation from the particle-hole excitations of the metal suppresses tunnelling[@Leggett87]. A finite cluster of spins coupled to a conduction electron bath is thus a model system for examining general issues of quantum coherence and dissipation in a system with many degrees of freedom. Also, recent experimental advances in atom manipulation[@Eigler93][@Eigler00] mean that clusters of atoms (eg. quantum corrals) can now be placed in controllable arrays on suitably chosen solid surfaces, so it seems likely that in the near future controlled magnetic nano-arrays may be constructed and studied.

In the case of a single spin in a metal, the interplay between tunnelling and dissipation gives rise to the logarithmic renormalizations characteristic of the one-impurity Kondo effect[@Anderson69]. While the two[@Jones87][@Castro00] and three[@Paul96] impurity Kondo problems have been studied, there is less known about the behavior of systems containing larger numbers of spins. The subject has been recently studied in the context of the “Griffiths phase” scenario for the non-Fermi-liquid physics apparently observed in certain ‘heavy fermion’ metals[@Stewart01]. To study this physics, Castro-Neto and Jones[@Castro00] considered a cluster of $N$ magnetic impurities, coupled strongly to each other and weakly to a conduction electron bath. They presented a series of qualitative arguments and approximate mappings from which they concluded that the system could undergo a more or less conventional Kondo screening (which they termed a “cluster Kondo effect”), at an $N-$dependent temperature which they estimated. The qualitative nature of the treatment suggests however that further analysis would be useful. One of us, with Morr and Schmalian[@Millis01], treated a similar problem of $N$ coupled moments from a functional integral point of view. In the Ising case, orthogonality effects were found to suppress tunnelling in all but the smallest nanostructures, while no definitive results were obtained in the continuous symmetry case.

In this paper we attack the problem from a different point of view. We identify a specific nanostructure, the finite-size spin necklace depicted in Fig.1. There are three motivations for this choice of cluster. First, it is (as can well be seen) amenable to a detailed analysis. Second, it exhibits large (but tractable) quantum fluctuations whereas in other works[@Castro00][@Millis01] the quantum fluctuations within the cluster are not taken into account. Third, we can treat the continuous symmetry case as well.

=2.2truein

[**Fig.1** Sketch of ‘spin necklace’ in conduction electron bath for $N=5$. Heavy dots represent local moments, which are coupled via an exchange coupling K. Shaded area represents conduction electron (c) sea, Kondo-coupled to local moments via exchange J.]{}

The Hamiltonian describing the physics of interest is $$\begin{aligned}
H &=&H_{necklace}+H_{cond}+H_{coupling}^{z}+H_{coupling}^{\perp } \\
H_{necklace} &=&\sum_{j=0}^{N-1}(K_{\bot
}(S_{j}^{x}S_{j+1}^{x}+S_{j}^{y}S_{j+1}^{y})+K_{z}S_{j}^{z}S_{j+1}^{z}) \\
H_{cond} &=&\sum_{k}\epsilon _{k}c_{k\sigma }^{\dagger }c_{k\sigma } \\
H_{coupling}^{z} &=&J_{z}\sum_{j=0}^{N-1}S_{j}^{z}(c_{{\bf R}_{j}\uparrow \
}^{\dagger }c_{{\bf R}_{j}\uparrow \ }-c_{{\bf R}_{j}\downarrow \ }^{\dagger
}c_{{\bf R}_{j}\downarrow \ }) \\
H_{coupling}^{\perp } &=&J_{\bot }\sum\limits_{j=0}^{N-1}(S_{j}^{+}c_{{\bf R}_{j}\downarrow \ }^{\dagger }c_{{\bf R}_{j}\uparrow }+S_{j}^{-}c_{{\bf R}_{j}\uparrow }^{\dagger }c_{{\bf R}_{j}\downarrow })\end{aligned}$$ with ${\bf R}_{j}$ the position of spin $j$. Here each spin value is $S_{j}=1/2$ and[** **]{}${\bf S}_{N}={\bf S}_{0}$. We restrict to the case of $K_{z}>-\left| K_{\bot }\right| $, so the ground state of $H_{necklace}$ is not ferromagnetic. We further specialize to $N$ odd so the ground state is characterized by a spin quantum number $S^{z}=\pm 1/2$. For $K_{\bot }<0$ the total momentum of each of the $S^{z}=\pm 1/2$ states is zero and the ground state is two-fold degenerate. For $K_{_{\bot }}>0$ the ground state also has non-zero total momentum $P=\kappa \left| P\right| ,$ $\kappa =\pm 1$ implying four-fold degeneracy. In this paper we focus on the limit in which the Kondo coupling, $J$, of the cluster to the conduction electrons is weak enough and the temperatures of interest low enough, that it is sufficient to consider only those spin flip processes that couple the degenerate ground states of the cluster. We expect that stronger couplings, implying mixing of higher energy states of the cluster, give rise to qualitatively similar physics. This case will be considered in a future paper[@Shah03].

If $H_{coupling}^{\perp }=0$, then the $z-$component of the cluster spin is a good quantum number. The cluster remains in a definite spin state, the conduction electrons just feel a potential due to the longitudinal coupling $J_{z}$, and the Hamiltonian $H_{0}=H_{necklace}+H_{cond}+H_{coupling}^{z}$ is easily diagonalized. For non-zero $J_{\bot }\ $ the problem is no longer trivially solvable. To study it, we use a perturbative expansion in $J_{\bot
}$ to establish a mapping onto a Coulomb gas, following the approach introduced by Anderson and Yuval[@Anderson69]. Let $\left| \Psi
_{\Uparrow }\right\rangle $ denote the ground state of $H_{0}$ when the cluster is in the $S^{z}=+1/2$ state, $\left| \Uparrow \right\rangle $ and consider the ground-state-to-ground-state amplitude (alternatively the partition function in the imaginary time formulation) given in the interaction representation by $$Z(t)=\left\langle \Psi _{\Uparrow }\left| e^{iH_{0}t}T\exp
[i\int\nolimits_{0}^{t}H^{\prime }(t^{\prime })dt^{\prime }]\right| \Psi
_{\Uparrow }\right\rangle$$ where $H^{\prime }(t)=e^{-iH_{0}t}H_{coupling}^{\perp }e^{iH_{0}t}$ and$\ T$ is the “time ordering operator”. Restricting to the ground state subspace of the cluster, and expanding to ${\cal O}(H^{\prime 2})$, $$\begin{aligned}
Z(t) &=&J_{\bot
}^{2}\int\nolimits_{0}^{t}dt_{1}\int\nolimits_{0}^{t_{1}}dt_{2}\sum_{{\bf R}_{i}}\sum_{{\bf R}_{j}}\left\langle \Uparrow \right| S_{i}^{+}\left|
\Downarrow \right\rangle \left\langle \Downarrow \right| S_{j}^{-}\left|
\Uparrow \right\rangle  \nonumber \\
&&\times F_{\uparrow }({\bf R}_{ij},t_{12})F_{\downarrow }({\bf R}_{ij},t_{12})  \label{Z2}\end{aligned}$$ where ${\bf R}_{ij}\equiv {\bf R}_{i}-{\bf R}_{j}$, $t_{12}\equiv
t_{1}-t_{2} $ and $$\begin{aligned}
F_{_{\uparrow }}({\bf R}_{ij},t_{12}) &=&\left\langle \Psi _{\Uparrow
}\left| Tc_{\uparrow {\bf R}_{i}}(t_{1})c_{\uparrow {\bf R}_{j}}^{\dagger
}(t_{2}){\cal S}(t_{12})\right| \Psi _{\Uparrow }\right\rangle \\
{\cal S}(t_{12}) &=&T\exp [-i\int\nolimits_{t_{2}}^{t_{1}}d\tau V(\tau )] \\
V(\tau ) &=&-2J_{z}\sum_{{\bf R}_{j}}\left\langle \Uparrow \right|
S_{j}^{z}\left| \Uparrow \right\rangle c_{{\bf R}_{j}}^{\dagger }(\tau )c_{{\bf R}_{j}}(\tau ).\end{aligned}$$ The expressions above are similar to the ones introduced in the context of the X-ray[@Nozieres69][@Gogolin] and the Kondo problem[@Anderson69], but with new features arising from the spatially extended nature of the magnetic object. The most important of these new features are the space dependence of $F$, arising from processes in which an electron is created at one site and destroyed at another, and a nontrivial dependence of matrix elements such as $\left\langle \Uparrow \right| S_{i}^{+}\left|
\Downarrow \right\rangle $ on necklace size and symmetry. We discuss these in turn.

Following Ref.[@Nozieres69] we express $F$ as the product of open line part $g=F/\left\langle {\cal S}\right\rangle $ and a closed loop part $\left\langle {\cal S}\right\rangle $ $\equiv e^{C}$ which may be computed by an expansion in $J_{z}$. The crucial object in this expansion is the Green’s functions $G({\bf r},t)$ of $H_{cond}$. We require the long time limit ($t\gg R/v_{F}$ with $R$ the radius of the necklace) in which $G({\bf r},t)\rightarrow \rho _{F}G({\bf r})/it$ : for a spherical Fermi surface $G({\bf r})=2\sin (k_{F}r)/v_{F}r$. In order to obtain a closed form for $g$ we exploit the specific geometry of the necklace. We parametrize the positions of the spins by the azimuthal angle $\phi _{j}=2\pi j/N,$ $j\in [0,N-1]$. Using $R_{kl}=2R\sin (\phi _{kl}/2)$, where $\phi _{kl}\equiv \phi _{k}-\phi
_{l}$, $G(R_{kl})\rightarrow G(\phi _{kl})$. We finally define the one-dimensional Fourier transform $$\begin{aligned}
G_{m} &=&\sum_{k-l=0}^{N-1}G(\phi _{kl})e^{im\phi _{kl}} \\
G(\phi _{kl}) &=&\frac{1}{N}\sum_{m}G_{m}e^{-im\phi _{kl}}\end{aligned}$$ where we choose $m=-\frac{N-1}{2},...0,...\frac{N-1}{2}$ to make the symmetry of the problem most apparent: $G_{-m}=G_{m}$. Using the $m-$basis and defining $V=-2J_{z}\left\langle \Uparrow \right| S_{i}^{z}\left|
\Uparrow \right\rangle $, $$\begin{aligned}
g(\phi _{ij},t_{12}) &=&\sum_{m}\frac{\rho _{F}G_{m}}{iN(t_{12})}e^{-im\phi
_{ij}}\left[ \frac{\tau _{c}}{t_{12}}\right] ^{2V\rho _{F}G_{m}} \\
e^{C(t_{12})} &=&\left[ \frac{\tau _{c}}{t_{12}}\right] ^{V^{2}\rho
_{F}^{2}\sum_{m}G_{m}^{2}}\end{aligned}$$ where $\tau _{c}$ is the short-time cut-off separating two spin-flips and we have neglected terms of ${\cal O}$($J_{z}^{3}$) in the exponent.

We now consider the matrix elements. We first note that if $K_{\bot }>0$ then the necklace ground states $\left| \Uparrow \right\rangle $, $\left|
\Uparrow \right\rangle $ have a nonvanishing momentum $\pm P_{\Uparrow
,\Downarrow }$ and the matrix element depends on the momentum transfer: $\left\langle \Uparrow \right| S_{j}^{+}\left| \Downarrow \right\rangle
=\left\langle \Uparrow \right| S_{0}^{+}\left| \Downarrow \right\rangle \exp
[iQj]$ where $Q=(P_{\Downarrow }-P_{\Uparrow })$. When $K_{\bot }>0$, the absolute value of the matrix element decays faster with $N$ when $P_{\Uparrow }=P_{\Downarrow }$. For $K_{\bot }>0$ when $P_{\Uparrow
}=-P_{\Downarrow }$ and for $K_{\bot }<0$ we find, defining $\alpha \leq 1$, $$\begin{aligned}
\left| \left\langle \Uparrow \right| S_{j}^{+}\left| \Downarrow
\right\rangle \right| &=&\left| \left\langle \Uparrow \right|
S_{0}^{+}\left| \Downarrow \right\rangle \right| \sim \frac{1}{N^{\alpha }}
\\
\left| \left\langle \Uparrow \right| S_{j}^{z}\left| \Uparrow \right\rangle
\right| &=&\left| \left\langle \Uparrow \right| S_{0}^{z}\left| \Uparrow
\right\rangle \right| \sim \frac{1}{N}.\end{aligned}$$

For $\left| K_{z}\right| \leq \left| K_{\bot }\right| $, in terms of the Jordan-Wigner fermion representation[@Lieb61], the states $\left|
\Uparrow \right\rangle $ and $\left| \Downarrow \right\rangle $ have different boundary conditions, one periodic and the other antiperiodic. Considering the low energy form of the Hamiltonian given by the Luttinger (massless) model and adopting the “boundary-condition changing operator” formalism[@Schotte69][@Affleck94] we find $$\begin{tabular}{ccccc}
$\alpha =\frac{1}{2}(1-\frac{1}{\pi }\cos ^{-1}\frac{K_{z}}{\left| K_{\bot
}\right| })$ &  &  & for & $\left| K_{z}\right| \leq \left| K_{\bot }\right|
$\end{tabular}$$ which we verify by a detailed numerical analysis (see Fig.2) of the exact lattice solution for the $K_{z}=0$ case ($xx-$model[@Lieb61]) for which $\alpha =1/4$.

=3truein

[**Fig.2** Plot of absolute value of $M=\left\langle \Uparrow \right| S_{j}^{+}\left| \Downarrow\right\rangle$ evaluated numerically for the $K_{z}=0$ case as a function of $N$. $\Delta _{\mu }$ is the matrix element when the Jordan-Wigner fermion is added (when spin is flipped) in the unoccupied momentum $k_{\mu }$, each of which contributes to $M$. The inset plots its real, imaginary parts and the absolute value as a function of $k_{\mu }$ for $N=283$. The maximum contribution is near the Fermi point. We find that $\left|M\right|$ is equal to $\left|\Delta _{0}\right|$ (obtained when $k_{\mu }$ is closest ($\mu = 0$) to the Fermi point) and when plotted against $N$, the two plots overlap.]{}

For the Ising case ($K_{z}=\infty $) for $K_{z}>0,$ the energy is minimized by having alternating up and down spins, but $N\;$being odd there is one frustrated bond with $N\;$possible locations for each of $S^{z}=-\frac{1}{2}$ and $\frac{1}{2}$. A perturbative analysis around this $2N-$fold degenerate point yields $$\begin{tabular}{ccccccc}
$\alpha =1$ &  &  &  &  & for & $K_{z}\gg $ $\left| K_{\bot }\right| .$\end{tabular}$$ We expect $\alpha =1$ for all $K_{z}>\left| K_{\bot }\right| $ (Ising regime).

The results for $\alpha $ indicate that it is much easier than one might guess, to flip a large cluster between its two ground states. Quantum fluctuations, which for example in the Ising regime delocalize the frustrated bond, bring about dramatic enhancement in the tunnelling caused by one spin flip by a conduction electron. By distributing $S^{z}=\pm 1/2$ over $N\;$sites, they also decrease the expectation value of $S_{j}^{z}$, thereby reducing the potential felt by the conduction electrons at each spin site.

We are now in a position to present our result for the ground-state-to-ground-state amplitude for the spin necklace embedded in a conduction bath, $$\begin{aligned}
Z(t) &=&\sum_{{\bf m}}u_{m}^{2}\int\nolimits_{0}^{t}\frac{dt_{1}}{\tau _{c}}\int\nolimits_{0}^{t_{1}}\frac{dt_{2}}{\tau _{c}}  \label{Z} \\
&&\times \exp \left\{ \left( 2-2\varepsilon _{m}\right) \ln \left[ \frac{\tau _{c}}{t^{\prime }-t}\right] \right\} \end{aligned}$$ where using $2\pi \widetilde{Q}/N=Q=(P_{\Downarrow }-P_{\Uparrow })$, $$\begin{aligned}
\varepsilon _{m} &=&\widetilde{J_{z}}[G_{m}+G_{m+\widetilde{Q}}]-\widetilde{J_{z}}^{2}\sum_{m^{\prime }}G_{m^{\prime }}^{2}  \label{em} \\
u_{m} &=&\widetilde{J_{\perp }}G_{m}G_{m+\widetilde{Q}}  \label{um}\end{aligned}$$ with $\widetilde{J_{\perp }}=J_{\perp }\rho _{F}\left| \left\langle \Uparrow
\right| S_{0}^{+}\left| \Downarrow \right\rangle \right| \sim J_{\perp }\rho
_{F}/N^{\alpha }$ and $\widetilde{J_{z}}=2\rho _{F}J_{z}\left\langle
\Uparrow \right| S_{0}^{z}\left| \Uparrow \right\rangle \sim J_{z}\rho _{F}/N
$. Note that since $\sum_{m}G_{m}^{2}\sim N$, the two terms in $\varepsilon
_{m}$ are of the same order in $N$ and its leading behavior is given by the term linear in $J_{z}\rho _{F}$ (assumed $\ll 1$). In the corresponding expression obtained in Ref.[@Millis01] it was assumed that only one channel was important and in the expression for $\varepsilon _{m}$, the term linear in $J_{z}$ was overlooked. The above expression for $Z$, Eq.(\[Z\]), is the second-order term in the expansion of a multicomponent Coulomb gas model in which each spin flip event (Coulomb gas charge) is labelled by the channel ($m-$value) of the electron-hole pair created. Higher order terms in the expansion in $J_{\perp }$ may be treated similarly, but compact expressions cannot be obtained because (as noted in a related context[@Fabrizio95]) in the multi-channel case, the higher order terms do not combine into the Cauchy determinant form[@Anderson69]. However we may define a scaling procedure as usual[@Anderson70] by eliminating close-pair spin flips of the same channel. To the leading order the different channels are not coupled, and standard arguments show that near the weak coupling fixed point, the partition function retains the form Eq.(\[Z\]) but with parameters $\varepsilon _{m}(\tau _{c})$ and $u_{m}(\tau
_{c})$ which evolve according to $$\begin{aligned}
d\varepsilon _{m}/d(\ln \tau _{c}) &=&2u_{m}^{2}  \label{se1} \\
du_{m}/d(\ln \tau _{c}) &=&u_{m}\varepsilon _{m}/2  \label{se2}\end{aligned}$$ with initial conditions given by Eq.(\[em\]) and (\[um\]). The flow implied by Eq.(\[se1\]) and (\[se2\]) is shown in Fig.3.

=3truein

[**Fig.3** Plot showing the flow for each channel, near the weak coupling fixed point. The heavy solid line is the separatrix $\varepsilon _{m}=-u_{m}/2$. The shaded oval region shows the generic initial conditions for the $xx$ symmetry. The dotted circle shows the generic initial conditions for the Ising limit. The striped region near $u_m=0$ is the range of initial conditions for ‘imperfect’ necklaces.]{}

For each channel the flow is to the no-flip fixed line ($u_{m}=0$) if $\varepsilon
_{m}<-u_{m}/2$ and towards the strongly coupled (rapidly flipping) regime (with $\varepsilon _{m}=u_{m}/2$) if $\varepsilon _{m}>-u_{m}/2$. Scaling amplifies the differences between channels. For example, in the $K_{\bot }<0$ case of the $xx-$model, the initial condition is $u_{m}^{0}=J^{\perp }\rho
_{F}G_{m}/N^{1/4}$ and $\varepsilon _{m}^{0}=2J_{z}\rho _{F}G_{m}/N$. For large $N$, $\varepsilon _{m}^{0}$ is thus parametrically smaller than $u_{m}^{0}$; all initial conditions are near the vertical axis and the dominant channels are those with the largest $G_{m}$. Representative results are shown in Fig.4. Note that for the ideal ring studied here, $G_{-m}=G_{m}$. We see that all channels with $m<Nk_{F}/2\pi $ couple with roughly equal strength, but generically there is one largest pair, so after a transient many channel regime, the asymptotic behavior is of the two-channel Kondo problem. Exceptions can occur, and in particular for $k_{F}\lesssim 2\pi /N$, the $m=0$ channel dominates. The same generic behavior occurs in other cases we have studied, but we note that in the Ising regime the $J_{z}$ and $J_{\bot }$ couplings are both $\sim 1/N$, so the initial conditions are shifted as indicated in Fig.3.

=3truein

[**Fig.4** Plot showing $G_m$ in the $K_{\bot }<0$ case of the $xx-$model for two values of $k_{F}$. For $k_{F}=\pi$, the pair $m = -10$ and $10$ and for $k_{F}=\pi/2$, the pair $m = -4$ and $4$ is the highest, constituting the dominant pair which governs the low energy behavior.]{}

To summarize: we have shown that the generic long-time dynamics of a spin necklace coupled to a conduction electron bath is of the two-channel Kondo class. We emphasize that generic deviations from perfect translation invariance break the two-channel symmetry. A key feature of the model is the large quantum fluctuations characteristic of the isolated necklace: these ensure that the dominant spin flip amplitude between the ground states of the spin necklace decays only as a power of the system size ($N^{-\alpha }$ with $0<\alpha \leq 1$) and that the static field exerted by the necklace on the conduction bath is small, of order $1/N,$ so “orthogonality” effects do not dominate. To explore the changes occurring as quantum fluctuations are reduced, we consider a necklace in the extreme Ising limit ($K_{z}\gg $ $\left| K_{\bot }\right| $) and with one weak link ($K_{z}^{01}\rightarrow
K_{z}(1-\delta )$) which acts to localize the frustrated bond. A detailed discussion and extension to other cases will be published elsewhere[@Shah03]. Here we note that although the residual reflection symmetry allows two channel behavior, the spin flip amplitude changes from $\sim 1/N$ to $\sim
\exp [-N\ln (K_{\bot }/\delta K_{z})]$ (moving the initial condition much closer to the $u_{m}=0$ axis of Fig.3). More importantly, because the frustrated bond is localized, the quadratic, “orthogonality” term in $\varepsilon _{m}$ (Eq.(\[em\])) becomes $\sim J_{z}^{2}N$, moving the initial condition substantially to the left (independent of the sign of $J_{z}$); and, for large enough $N$, into the stable (no asymptotic flip) region.

Extensions of the present work include a treatment of systems with open boundary conditions, and of other nanostructures. We expect generically that internal quantum fluctuations of a nanoscale object (neglected in many treatments, Ref.[@Castro00] and [@Millis01] for example) will have a dramatic effect on the long time dynamics.

Acknowledgments: We thank L. B. Ioffe for helpful discussions and NSF-DMR-00081075 for support.

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