**7. High-resolution transmission electron diffraction**

The original form of electron microscope, the transmission electron microscope (TEM) uses a high voltage electron beam to create an image. The electron beam is accelerated by an anode with respect to the cathode, focused by electrostatic and electromagnetic lenses, and transmitted through the sample that is in part transparent to the electrons and in part scatters them out of the beam. When it emerges from the sample, the electron beam carries information about the structure of the sample that is magnified by the objective lens system of the microscope. Hardware correction of spherical aberration for the high-resolution transmission electron microscopy (HRTEM) has allowed the production of images with resolution below 0.5 Å at magnifications above 50 million times. This possibility of having direct images of the atomic arrangement in the structure has made the HRTEM an important tool for nano-technologies research and development.


**1. Introduction**

For warm stamping of stainless steels and light alloys, the molds are operated at high temperature—thermal and load cycling—and often lose effectiveness early because of oxidation and wear. The plasma nitriding process (PN) is a well-known technique, which can be utilized to improve the surface properties of ferrous alloys [1,2]. Similar to PN, physical vapor deposition (PVD) techniques make coatings useful for tool steels with good tribological performance due to high hardness, anti-abrasion, and high-temperature oxidation resistance. However, their mechanical performance is restricted when they are deposited on a soft substrate due to plastic deformation under high loads without adequate support. Duplex treatments including PN and PVD are verified to be successful in creating wear and corrosion resistance with good mechanical support. The adhesion strength between the coating and the tool steel can be controlled by nitriding techniques and gradient coating designs to tailor the nitrided layer and by inserting a surface treatment method, such as polishing, before the deposition of hard coatings [3–6].

Currently, PVD hard coatings such as CrN, TiN, CrAlN, and TiAlN are used to improve the properties of tool steels and extend the lifetime of mechanical components and tools [7–11]. The introduction of silicon into CrAlN could decrease the grain size, change the coating structure, composition, and its mechanical properties [12–14]. In this CrAlSiN, silicon is apt to segregate into amorphous SiNx along the grain boundaries. Many nanocomposite and nanolayered coatings have been studied due to their excellent mechanical and tribological properties. The coating

structure and chemical content of the film can influence the mechanical and tribological properties of multicomponent coatings in the form of gradient and multilayered layers. Previous studies have shown that multilayered and graded coatings, such as AlCrSiN/TiVN and TiVN/TiSiN, are very effective in reducing wear in molding, forming, and machining applications [15–17]. High-speed steels and hot-working steels are the universal stamping, cutting, and machining tool steels because of their good strength at high temperature and are usually used for metal forming, cutting tools, and light alloy injection. However, these tool steels have poor resistance to tribological wear with a high coefficient of friction. The demand has been increased using surface modification and coating techniques to improve the mechanical and wear performances of the tool steel. Thermal-and-chemical surface modification such as PN is applied to these steels for prolonging the lifetime of tools [18]. This study tried to develop plasma nitriding before the AlCrSiN hard coating deposition to improve the mechanical properties of tool steel substrates and the adhesion strength. An impact fatigue test was conducted at room temperature and at high temperature. The purpose was to study the microstructure, mechanical properties, and periodic impact resistance of the high-speed steels with duplex treatment combing PVD AlCrSiN coatings and PN.


**Author details**

Seema Kaushal\* and Hena Khandakar Department of Pathology, All India Institute of Medical Sciences, New Delhi, India

\*Address all correspondence to<EMAIL_ADDRESS>
© 2021 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


**2. Role of thyroid hormones in bone growth and metabolism**

Thyroid hormones are critical for the skeletal development and the bone maintenance. The thyroid hormone, 3,5,3'-triiodothyronine (T3), is responsible for major actions of thyroid hormones. T3 binds to nuclear receptors that regulate gene transcription via interaction with thyroid hormone response elements of specific genes (Sap et al., 1986; Weinberger et al., 1986; Thompson et al., 1987). Recently, non-genomic actions of T3 and T4 have been described (Cheng et al., 2010). Local tissue availability of T3 seems to be regulated by type 2 and 3 deiodinase (St Germain et al, 2009). The nuclear thyroid hormone receptors (TRs) are derived from the THRA and THRB genes coding for the TRα1 and β1-2 T3-binding isoforms, truncated isoforms ∆α1, ∆α2 and ∆β3, and a TRa2 non-T3-binding isoform of unknown function (Lazar et Chin et al, 1990; Lazar, 1993; Chassande et al, 1997; Williams, 2000; Cheng et al, 2010). Expression of TRα1 and TRβ1 was described in growth plate chondrocytes, osteoblasts, and stromal cells of bone marrow (Williams et al, 1994; Abu et al, 1997; Ballock et al, 1999; Bradley et al, 1992; Bassett et Williams, 2003; Siddiqi et al, 2002). Expression of TRα in the skeleton is higher than that of TRβ (Bookout et al, 2006; O'Shea et al, 2003).

Thyroid Disorders and Bone Mineral Homeostasis 253

partially reverted skeletal development and maturation defects in hypothyroid rats (Freitas

Thyroid hormones regulate bone development also indirectly through the growth hormone (GH) and insulin-like growth factor-I (IGF-I) axis. Previously, it was demonstrated that T4 enhanced the growth promoting effect of GH/IGF-I (Thorngren et Hansson, 1974) and could stimulate longitudinal bone growth in hypophysectomized rats (Thorngren et Hansson, 1973; Ray et al, 1954). T3 was shown to interact with the thyroid hormone receptor - thyroid hormone responsive element complex (TR-TRE) in the GH promoter to regulate GH gene transcription (Glass et al, 1987; Koenig et al, 1987). However, GH without T3 did not promote the maturation (Ballock et Reddi, 1994) and organization (Lewinson et al, 1989) of growth plate chondrocytes and GH replacement could not rescue the impaired ossification in TRα and TRβ-null mice (Kindblom et al, 2001). In TRα1−/−β−/− mice, GH substitution reversed the growth phenotype, but not the defective ossification (Kindblom et al, 2001). On the other hand, inactivation of GH or IGF-I receptors in mice was associated with delayed

Overall, the literature data indicate importance of both TRs and GH-IGF-I axis in skeletal development. Other factors, such as the Indian Hedgehog (Ihh), parathyroid hormonerelated peptide (PTHrP), fibroblast growth factor receptor and Wnt--catenin signaling pathways, are implicated in this process (Barnard et al, 2005; O'Shea et al, 2005; Stevens et al, 2000, 2003; Wang et al, 2007). Further studies are warranted to clarify the exact

Literature evidence points to the critical importance of thyroid hormones in bone remodeling and maintenance. Adult euthyroid mice invalidated for TRα have reduced osteoclastic bone resorption and increased trabecular bone volume and mineralization (Bassett et al, 2007a, 2007b), indicating a critical role of TRα in T3 action in bone cells. On the other hand, increased osteoclastic bone resorption and severe osteoporosis were demonstrated in adult TRβ mutant mice, suggestive of thyroid hormone excess in TRαexpressing skeletal cells (Bassett et al, 2007a, 2007b; Gauthier et al, 2001; O'Shea et al, 2006).

The bone architecture and strength are maintained by a balanced process of remodeling, which involves recruitment of osteoclast and osteoblasts. T3 can induce differentiation and inhibits proliferation of osteoblastic cells. T3 was shown to promote production of IL-6, IL-8, IGF-I and its binding proteins IGFBP2-4 in bone marrow stromal cells and osteoblasts (Milne et al, 2001; Siddiqi et al, 1998), and to increase the expression of several bone-related genes, including osteocalcin, collagen type I, gelatinase B and collagenase 3 (Gouveia et al 2001; Milne et al 1998; Pereira 1999; Varga et al 1997; Williams et al 1994). T3 is implicated in chondrogenesis, angiogenesis, bone matrix formation and mineralization (Himeno et al, 2002; Makihira et al, 2003; Pereira et al, 1999). In primary cultures of growth plate chondrocytes, T3 inhibits chondrocyte clonal expansion and cell proliferation, induces hypertrophic chondrocyte differentiation and promotes cartilage matrix mineralization (Robson et al, 2000).

mechanisms underlying the physiological regulation of bone development.

et al, 2005). This finding is suggestive of TRβ1 involvement in bone growth.

ossification (Liu et al, 1993; Sjogren et al, 2000).

**2.2. Thyroid hormone and bone remodeling**

### **2.1. Thyroid hormone and bone development**

Studies on animal models have brought valuable insights into role of TRs in bone development and growth. Mice lacking TRβ or TRα1 did not display abnormalities in skeletal development (Forrest et al, 1996; Wikstrom et al, 1998). On the other hand, genetic disruption of both receptors (TRα1 and TRβ) led to delayed ossification and disorders in development of epiphyseal growth plates (EGPs; Gothe et al, 1999). Pax-8−/− mice, expressing all TR isoforms, but lacking the follicular cells producing T4 and T3 in the thyroid gland, displayed more severe abnormalities in bone development than mice KO for all TRs (TRα0/0, TRβ−/−) (Flamant et al, 2002). The authors concluded that the unliganded TRs (aporeceptors) on thyroid hormone responsive genes have repressor effects during bone development. In support of this, Pax-8−/−TRα0/0, but not Pax-8−/−TRβ−/−, compound mutants presented a partial rescue of the bone phenotype (O'Shea et Williams, 2002; Flamant et al, 2002). Another study was realized employing mice invalidated for TRα. These animals were euthyroid, but displayed a growth delay with abnormal bone development and ossification (Bassett et al 2007a, 2007b; Gauthier et al, 1999, 2001; O'Shea 2003, 2005). Mice lacking all TRα isoforms presented a less severe impairment of bone development than TRα-/- mice, pointing to the role of non-T3 binding TRα isoforms (∆α1 and ∆α2) (Gauthier et al, 2001). On the other hand, mice with nonfunctional TRβ displayed augmentation in circulating thyroid hormone levels associated with dysregulation of hypothalamo-pituitary-thyroid axis. These animals had skeletal signs of hyperthyroidism, increased bone mineral deposition and acceleration of growth-plate maturation, resulting in a short adult body size (Bassett et al, 2007a; O'Shea et al, 2003). These findings suggested an increased skeletal response to T3 via TRα, which was consistent with the hypothesis that elevated circulating thyroid hormone levels in TRβ mutant mice result in an increased skeletal response to T3 via TRα (O'Shea et al, 2006). Recently, GC-1, thyroid hormone analogue targeting preferentially TRβ1 over TRα1, has partially reverted skeletal development and maturation defects in hypothyroid rats (Freitas et al, 2005). This finding is suggestive of TRβ1 involvement in bone growth.

Thyroid hormones regulate bone development also indirectly through the growth hormone (GH) and insulin-like growth factor-I (IGF-I) axis. Previously, it was demonstrated that T4 enhanced the growth promoting effect of GH/IGF-I (Thorngren et Hansson, 1974) and could stimulate longitudinal bone growth in hypophysectomized rats (Thorngren et Hansson, 1973; Ray et al, 1954). T3 was shown to interact with the thyroid hormone receptor - thyroid hormone responsive element complex (TR-TRE) in the GH promoter to regulate GH gene transcription (Glass et al, 1987; Koenig et al, 1987). However, GH without T3 did not promote the maturation (Ballock et Reddi, 1994) and organization (Lewinson et al, 1989) of growth plate chondrocytes and GH replacement could not rescue the impaired ossification in TRα and TRβ-null mice (Kindblom et al, 2001). In TRα1−/−β−/− mice, GH substitution reversed the growth phenotype, but not the defective ossification (Kindblom et al, 2001). On the other hand, inactivation of GH or IGF-I receptors in mice was associated with delayed ossification (Liu et al, 1993; Sjogren et al, 2000).

Overall, the literature data indicate importance of both TRs and GH-IGF-I axis in skeletal development. Other factors, such as the Indian Hedgehog (Ihh), parathyroid hormonerelated peptide (PTHrP), fibroblast growth factor receptor and Wnt--catenin signaling pathways, are implicated in this process (Barnard et al, 2005; O'Shea et al, 2005; Stevens et al, 2000, 2003; Wang et al, 2007). Further studies are warranted to clarify the exact mechanisms underlying the physiological regulation of bone development.


The vision of development through education that the FRELIMO government chose to pursue was deeply intertwined with the country's colonial past. Considering that at the time of independence more than 90% of the Mozambican population were illiterate,41 educational policy primarily concentrated on countrywide literacy campaigns for children and adults to address the overwhelming patterns of exclusion inherited from the colonial education system.42 With regard to under-representation in higher education, it might be helpful to note that, although in 1970 about 98% of Mozambique's population were of African origin,43 by 1975 only 1–2% of university students were African.44 Such fgures illustrate the unequal access to higher education that existed during the colonial period, resulting in a severe lack of academically and technically qualifed Mozambican cadres. In addition, the colonial administration and economy had heavily relied on Portuguese and immigrant personnel to fulfl leadership positions. This meant that the FRELIMO government inherited a state apparatus with mostly underqualifed Mozambican cadres in 1975. Furthermore, by 1976 about 200,000–250,000 Portuguese citizens left the country, resulting in a dramatic loss of expertise and technical knowledge in the young nation state's administration and economy.45 Consequently, the

41Estimations range from 85 to 97% of the population, see Barnes, "Education for Socialism," 406; Mário Mouzinho and Deborah Nandja, "Literacy in Mozambique: Education for all Challenges," paper commissioned for the "Education for All" (EFA) Global Monitoring Report 2006, Paris: UNESCO; Maputo: UEM, Faculty of Education, http:// unesdoc.unesco.org/images/0014/001462/146284e.pdf.

42Agneta Lind, *Adult Literacy Lessons and Promises: The Mozambican Literacy Campaigns, 1978*–*1982* (Stockholm: Institute of International Education, 1988).

43The source reports that 2% of the population in Mozambique were "whites" in 1970 and mentions a decline of the white population after 1974–1975, to a level of 0.2% in 1983, see Statistisches Bundesamt, *Länderbericht Mosambik* (Stuttgart: Metzler-Poeschel, 1989), 23.

44Peter Fry and Rogério Utui, "Promoting Access, Quality and Capacity-Building in African Higher Education: The Strategic Planning Experience at the Eduardo Mondlane University" (Washington: ADEA Working Group on Higher Education, The World Bank, 1999), 2–3, http://www.adeanet.org/adea/publications/wghe/wghe\_uem\_en.pdf.

45Barnes, "Education for Socialism," 406; Statistisches Bundesamt, *Länderbericht*, 18; Newitt, *Short History*, 151.

lack of local clerks and functionaries became a major problem facing the state-building process after independence, and a key obstacle to the prosperous development envisioned by FRELIMO.

In response to this twofold colonial legacy, FRELIMO's priority was the education of a national intelligentsia, alongside the general goal of introducing education for all.46 Education was perceived as a prerequisite to securing national independence; this somewhat heroic stance on education was vividly demonstrated in slogans like "study, combat, produce!"47 Unfortunately, FRELIMO had to build up its leadership cadres and "prepare the 'working class for the control of the economy' […] without an adequate social base,"48 while facing a serious lack of fnancial resources. In such a situation, FRELIMO resolved to rely on the experience it gained during its struggle for independence from Portugal (1964–1974), during which, the areas under its control (*zonas libertadas*) successfully introduced an embryonic education system for liberation fghters and their children.49 Besides this experience for self-reliance50 in education, FRELIMO relied on educational aid from socialist states, as well as from supporting actors from around the non-socialist world, to realize its educational goals.51

Gradually, nationwide educational policies were introduced by the FRELIMO government, starting with the nationalization of all educational institutions as decreed in September 1975, and followed by the foundation of the Mozambican Education Ministry (MEC), which

#### 46Johnston, *Mozambican State*.

47Anthon Johnston, *Study, Produce, and Combat! Education and the Mozambican State 1962*–*1984* (Stockhom: Institute of International Education, University of Stockholm, 1989).

48Cross, *Unfulflled Promise*, 61.

49Johnston, *Mozambican State*, 280–282; Salvador André Zawangoni, *A FRELIMO e a Formação do Homem Novo, 1964*–*1974 e 1975*–*1982* (Maputo: *CIEDIMA*, 2007).

50The frst FRELIMO-led schools were run by exiles in Tanzania, and FRELIMO's struggle for independence benefted from the generous hospitality that the Tanzanian government granted to anti-imperialist liberation movements. Therefore, it is likely that FRELIMO educators were at least partly inspired by the concept of African *self*-*reliance*, as propagated by the Tanzanian president Nyerere; see Cross, *Unfulflled Promise*, 52–53, 61–62.

51José P. Castiano, *Das Bildungssystem in Mosambik (1974*–*1966): Entwicklungen, Probleme und Konsequenzen* (Hamburg: Institut für Afrika-Kunde, 1997), 128.

started to function in February 1976.52 In May 1976, the country's only institution of higher learning was renamed *Eduardo Mondlane University* (UEM), after the founding member and frst president of FRELIMO.53 A year later, the decision for socialism as a state ideology was offcially confrmed during the III FRELIMO Congress, during which FRELIMO turned from a liberation movement into a "vanguard party" (called the Frelimo Party) with a Marxist–Leninist political orientation.54 As a consequence of the congress of 1977, "Education for Socialism"55 became the leitmotif in the following orchestration of educational policies. Nevertheless, in 1979 the majority of students in most UEM faculties still originated from middle-class backgrounds56; in the mid-1980s only about 11% of university students were from families with worker–peasant backgrounds.57 These statistics did not ft the socialist outlook of the university as planned by the Frelimo Party, because it was doubted that middle-class members would support Frelimo's path of socialist development. To counteract trends labeled as "petit bourgeois" at the UEM, Frelimo introduced regulations favoring students with worker–peasant backgrounds for entry to university, hoping that they would naturally align themselves with the socialist project.58 Thus, the educational goals set by Frelimo involved "an education system to cater for workers and their children at all levels, the development of an education system at the service of society […], and the breakdown of the barriers between theory

54FRELIMO, "Ökonomische und soziale Direktiven," in *Dokumente des 3. Kongresses der FRELIMO*, ed. by Informationsstelle Südliches Afrika (Bonn: Issa, 1978), 139–190.

55Cross, *Unfulflled Promise*, 76.

56See report "Halbjahresbericht 2/79 der DDR-Lehrkräfte an der Universität "Eduardo Mondlane" signed by Dora on 30 January 1980 (BArch/DR3/II.Schicht/1540).

57Lewin et al., *Die Herausbildung*, 43.

58FRELIMO, *Direktiven*, 187.

52Ibid., 85–86.

53The institution was founded in 1962 in the city of Lourenço Marques (today Maputo) and acquired the status of a university in 1968. The name of the colonial *University of Lourenço Marques* referred to a Portuguese "discoverer" of the sixteenth century. Therefore, the post-independence renaming of the university after a pioneer of the liberation struggle was as symbolic act highlighting the history of anticolonial resistance. See Frey and Utui, "Promoting Access," 2–3; Mouzinho Mário et al., *Higher Eduaction in Mozambique: A Case Study* (Oxford: James Currey; Maputo: Imprensa & Livraria Universitária UEM, 2003), 7.

and practice or study and production."59 These post-independence socialist goals were integrated into the frst Mozambican national education system (*Sistema Nacional de Educação*, SNE), which only came into effect in 1983.60

In the feld of higher education, the SNE regulated that the UEM should, frst and foremost, educate scientifc and technical cadres to meet the demands of the state, economy, and society. The teaching conducted at the UEM was meant to contribute to the overall (socialist) development of the country, by providing politically, culturally, and not least ideologically educated graduates. Furthermore, Frelimo's development goals did materialize in the organizational structure of the UEM when, for instance, two new faculties were created: one exclusively devoted to the new state ideology of Marxism–Leninism, and another meant for the explicit qualifcation of adult students with worker–peasant backgrounds. Curiously, from 1983 onward, this later faculty was also in charge of training former FRELIMO fghters and experienced workers (worker students), who actually did not have an adequate educational background for entry to university.61 Another such exception was made for students applying for minor teacher-training courses at the Faculty of Education, where nine years of prior schooling was accepted as a pre-requisite to university entry.62 Despite offensives to promote university access, graduate numbers stagnated, while the demand for national and loyal cadres in state apparatus and state enterprises remained high throughout the post-independence period.63

#### 59Cross, *Unfulflled Promise*, 76.

60For a detailed description of the post-independence development of Mozambique's education sector see Johnston, *Mozambican State*; Brazão Mazula, *Educação, Cultura e Ideologia em Moçambique: 1975*–*1985. Em busca de fundamentos flosófco*-*antropológicos* (Porto: Edições Afrontamento, 1995); Castiano, *Bildungssystem*; Buendía Miguel Gómez, *Educação Moçambicana. História de um processo: 1962*–*1984* (Maputo: Livraria Universitária, UEM, 1999); Cross, *Unfulflled Promise*.

61See leafet "O que é o Curso Pré-Universitário da Faculdade de Antigos Combatentes e Trabalhadores de Vanguarda," UEM, Maputo, November 1985 (AHM/documentation Ganhão/box 16); Castiano, *Bildungssystem*, 112.

62It was usually required to pass the 10th and 11th grade of regular schooling before entry to university. Ibid., 102.

63Anton Johnston, *Educação em Moçambique: 1975*–*1984* (Stockholm: SIDA, 1986).

Ironically enough, while the UEM was responsible for educating university-trained personnel, the university itself suffered from a severe lack of academic staff. To enhance national university staff qualifcations, a practice of "training on the job" became widespread at the UEM; Mozambican assistants, so-called *monitores,* were included within the teaching staff. Such *monitores* were mostly undergraduate students of Mozambican origin, who were already delivering lectures to younger fellow students and assisting regular—mostly foreign—lecturers at the UEM.64 In that light, the massive employment of foreign advisors and teaching staff served frst as a relief mechanism to keep the university functioning, and second, contributed to the training of local UEM staff. This was especially true for the ad hoc qualifcation of national cadres, as exemplifed in the case of Mozambican *monitores*. Nevertheless, by 1980 this employment policy led to a situation in which 79% of the teaching staff employed at the UEM were of foreign origin.65 We will later see that the recruitment of foreign cooperators "had serious political and pedagogical implications"66 for the whole education sector. Still, a partial success in the "Mozambicanization" process of UEM structures was reported by East German cooperators in 1981, when leadership of three university faculties was handed over to Mozambican cadres.67 Details in East German reports reveal that the cooperators were well aware of their "mission" to improve the level of qualifcation of Mozambican staff; such reports also hint that East German cooperators perceived themselves as supportive colleagues at the UEM.

64Hegewald, "Berlin, Maputo," 470, 476.

65See statistical chart "Evolução dos docentes da UEM de 1980 a 1983" (BArch/DR3/ II.Schicht/1539).

66Cross, *Unfulflled Promise*, 74.

67See report "Halbjahresbericht I/1981, Bereich Gesellschaftswissenschaften" by the GDR teaching staff at the UEM, signed by Schlauch, Maputo, 10 June 1981 (BArch/ DR3/II.Schicht/1540), concerning the following faculties: Law, Education, and Marxism– Leninism (p. 7).

# East German Involvement in Mozambique's (Socialist) Development and International Cooperation in Higher Education

While exerting their "socialist solidarity" duties on campus, East German lecturers were formally embedded in a wider system of bilateral cooperation. Notably, educational cooperation between Mozambican and East German protagonists began during the struggle for liberation, namely in a FRELIMO school based in Tanzania set up by Mozambican exiles in 1967.68 Before that, FRELIMO President Mondlane visited the GDR in 1966,69 looking for support for Mozambican liberation.70 FRELIMO was not yet a political party, but an anticolonial movement, therefore, an intergovernmental basis for regulating services of "socialist solidarity" was temporarily missing. Nevertheless, on behalf of GDR's "Solidarity Committee" (*Solidaritätskomitee*) a handful of GDR teachers and educational advisers were sent to Tanzania, and later to the "liberated zones" in northern Mozambique, to support FRELIMO's educational programs prior to independence.71 Interestingly, at that time knowledge about Mozambique and the liberation movement FRELIMO was very limited in the GDR, illustrated by the East German authorities' uncertainty about Portuguese as lingua franca within FRELIMO.72 The frst GDR "expert" sent to a FRELIMO-run school,73 for instance, only spoke

68For a more sophisticated report on this early stage of GDR–Mozambican cooperation in education see Hans-Jochen Roos, "Unterrichten unter Palmen. Als Biologielehrer an der FRELIMO-Schule in Bagamoyo," in *Wir haben Spuren hinterlassen!* ed. by Matthias Voß, 407–425.

69Tullner, "Zusammenarbeit," 389.

70During the liberation struggle, FRELIMO succeeded to mobilize a wide network of international supporters in socialist and non-socialist countries, and was engaged in the non-alignment movement. See António da Costa Gaspar, "Frente Diplomática," in *História da Luta de Libertação Nacional*, vol. 1, ed. by Joel de Neves Tembe (Maputo: Ministério dos Combatentes, 2014), 87–188.

71Matthias Voß and Achim Kindler, "Um de nós – einer von uns! Gespräch mit Achim Kindler, der als Lehrer im Auftrag des Solidaritätskomitees der DDR als erster DDR-Bürger bei der FRELIMO arbeitete," in *Wir haben Spuren hinterlassen!* ed. by Matthias, 34–46.

72Tullner, "Zusammenarbeit," 389.

73This secondary school (*Instituto Mozambicano*) was run in Dar-es-Salaam, Tanzania.

English. As no suitable Portuguese language course was available in the GDR, he brought a Spanish dictionary with him to improvise communication. Offcial instructions concerning the mission of GDR cooperators in FRELIMO-run schools appeared to be rather vague during that period.74 This initial situation changed over time and Mozambique became a priority in the framework of the GDR's solidarity engagement in Africa, and educational aid came to play a major role within the concept of "socialist solidarity" for the young People's Republic.75 In the feld of higher education, at times, up to 42 GDR cooperators were simultaneously working at the UEM, distributed among all twelve faculties.76

Concerning the practice of recruiting at the UEM, it is relevant to mention that the GDR sent advisors and lecturers only on the request of its Mozambican counterparts. East German cooperators were then contracted to carry out specifc tasks that were defned by the Frelimo government.77 One such project was the creation of a special "workers' faculty" at the UEM.78 Although the creation of this faculty represented a comparatively small part in the overall scope of responsibilities carried out by GDR cooperators at the UEM, its founding process may serve as an interesting example of the practice of international cooperation

76Highest number of GDR staff at the UEM registered in the period 1976–1989; the source does not reveal the concrete date, but it states that most of the GDR cooperators in that group worked for the Faculty of Engineering (28), followed by the Faculty of Education and the Faculty of Economy (both 15), and the Faculty of Medicine (12). In 1984, for instance, 30 GDR cooperators were working in the higher education sector. See Hegewald, "Berlin, Maputo," 467, 471.

77Corresponding working plans were agreed upon in special annexes to signed treaties of friendship and cooperation, which in the case of Mozambique was signed on February 24, 1979 (BArch/DR3/II.Schicht/B 1542). Also see Hans-Georg Schleicher, "Spurensuche im Süden Afrikas. Die Zusammenarbeit mit den Befreiungsbewegungen wirkt nach," in *Ostalgie international. Erinnerungen an die DDR von Nicaragua bis Vietnam*, ed. by Thomas Kunze and Thomas Vogel (Berlin: Ch. Links, 2010), 49.

78See report "Bericht zur Einrichtung einer ABF-ähnlichen Einrichtung an der UEM" by Strobel 1981 (BArch, DR3, II. Schicht, 1540); see also "Bericht über die Arbeit der Ökonomischen Fakultät (II. Halbjahr/1980) der AG-Universität Maputo" by Dora, including "Anlage zum Halbjahresbericht II/1980 der AG der DDR-Lehrkräfte an der UEM" to the MHF, Maputo, 14 November 1980 (BArch, DR3, II. Schicht, 1540).

74Voß and Kindler, "Um de nós," 35–36, 39; Tullner, "Zusammenarbeit," 389.

75Müller, *Bildungshilfe*; Schuch, *Mosambik*, 22–23.

at the university. To begin with, the requested faculty was supposed to take in adult students from the working class at pre-university level and prepare them in an accelerated manner for entry to university.79 Comparable institutions called "worker–peasant faculties" existed in East German universities until 1963,80 and cooperators from the GDR brought with them their own ideas about how a similar faculty could be implemented into the Mozambican context.81 The actual founding process of the Mozambican "workers' faculty" lasted from 1979 to its opening in 1983 and personnel from Mozambique, the GDR, as well as Portugal and Chile were prominently involved in the conception of the faculty throughout the process. Although possible "role model" institutions existed in the GDR—and other socialist countries, such as Cuba or the Soviet Union—cooperators in charge remained reluctant to push through homegrown concepts where they considered them unsuitable. Final decision-making power on the design of a "workers' faculty" at the UEM resided with Mozambican actors, that is, the Frelimo Party.82 As a result, a rather Mozambican version of a "workers' faculty" was established and fttingly named the "Faculty for Former Combatants and Vanguard Workers," because former liberation fghters constituted one of its target groups. The formation process of this "workers' faculty" exemplifes that educational transfers from abroad did not work in one direction only at the UEM, and that foreign cooperators were not always

79FRELIMO, "Direktiven," 187.

80For the history of worker–peasant faculties in the GDR see Ingrid Miethe, *Bildung und soziale Ungleichheit in der DDR. Möglichkeiten und Grenzen einer gegenprivilegierenden Bildungspolitik* (Opladen: Barbara Budrich, 2007).

81It is very likely that all GDR cooperators had a notion of the worker–peasant faculty called "ABF" in the GDR. Even Berthold Brecht devoted a poem to the ABF, and the East German writer Hermann Kant wrote a well-received novel on the ABF. See John Connelly, *Captive University: The Sovietization of East German, Czech, and Polish Higher Education, 1945*–*1956* (Chapel Hill, London: The University of North Carolina Press, 2000), 281. Kant's book "Die Aula" was "among the most printed books in the GDR," ibid., 397.

82See "Zur Einschätzung der Arbeit im Rektorat," report by Hr. Urbanski to MHF, Maputo, 19 June 1981 (BArch/DR3/II. Schicht/1540). For more examples on GDR– Mozambican cooperation see interviews with former UEM lecturers in Lisbon, Maputo, and Rostock, February to November 2014. Also see Dora, *Kokos*, 85–87; Tullner, "Zusammenarbeit," 396–403.

able or willing to assert their homegrown models within the framework of multinational cooperation.83

# East German Advisers at the UEM and Internationalist Practices "on the Ground"

The everyday work of East German cooperators at the UEM will be depicted in the following sections of this chapter mainly through examples from three university departments, namely the Faculty of Education (Teacher Training Faculty), the Faculty of Marxism–Leninism, and the Faculty for Former Combatants and Vanguard Workers.84 The fndings collected indicate that "socialist solidarity" at the UEM was accompanied by intercultural misunderstandings and ideological differences. But, besides these rather negative aspects of international cooperation, the remarkable motivation of GDR staff "to make things work" was noticeable.

### *Intercultural Encounters*

In relation to their Mozambican partners, interviews and memoirs produced by GDR cooperators point toward a relative openness for intercultural learning. But GDR cooperators also had to deal with partners from non-socialist countries, and many GDR cooperators encountered some—more or less harsh—diversity shocks during their mission at the UEM. In 1981, for example, the Faculty of Education had "a very international teaching staff with lecturers from socialist countries (USSR, GDR, Cuba, Bulgaria), approx. 26 lecturers from non-socialist countries,

83Tim Kaiser et al., "Educational Transfers in Postcolonial Contexts: Preliminary Results from Comparative Research on Workers' Faculties in Vietnam, Cuba, and Mozambique," *European Education* 47, no. 3 (2015): 252–255; Alexandra Piepiorka, "Sozialistische Hochschulpolitik im Mosambik der 1980er Jahre. Das Beispiel der Fakultät für ehemalige Kämpfer\*innen and Arbeiter\*innen," in *Sozialismus & Pädagogik: Verhältnisbestimmungen und Entwürfe*, ed. by Sebastian Engelmann and Robert Pfützner (Bielefeld: Transcript, 2018), 173–196.

84All three faculties seem rather unusual when compared with "classic" university structures, but in socialist universities similar departments can be found. In the Soviet Union, for instance, teacher training institutes, departments of Marxism–Leninism, and "workers' faculties" existed in the higher education sector; see Connelly, *Captive University*.

and 8 Mozambicans."85 In face of this situation most GDR cooperators kept a critical distance to their colleagues from non-socialist countries, even though many of them had left-wing views. Apparently, the left-wing background of people from non-socialist countries was quite different from the experience of state socialism that was familiar to GDR citizens. In offcial reports, "Western" socialists were sometimes labeled as "leftwing extremists" by GDR cooperators.86 Nevertheless, GDR cooperators embraced the possibilities of observing the unknown "other" and, in some cases, even chose to befriend some of their left-wing colleagues from the "West."87

An anecdote from the Faculty of Combatants seems telling in the context of diversity at the UEM. The pedagogical director of that faculty was a communist Chilean and generally recognized for his expertise in the feld of adult education. He was described as a person who had a very positive infuence on the students within the faculty, but due to his spontaneity, used to come up with new pedagogical concepts once in a while.88 His East German colleague, on the other hand, was respected for this systematic working routine and his well-planned course of action. The collaboration of both characters within the international team of the faculty thus lead to frequent quarrels, and to amusement on the side of their Mozambican supervisor: "Jorge and Hans were always discussing with each other, all the time, all the time, all the time. Hans was very German, and Jorge was very Latin … [laughs] so Hans was very organized, and Jorge had a new idea every day. And Hans did not really like new ideas on a daily basis. [laughs] He preferred to bring things to an end. So both of them had [intercultural, AP] shocks, but these were friendly shocks. They hang out together from the beginning until the

85See report "Gruppe Maputo/UEM – Jahresbericht 1981, Teilbericht Gesellschaftswissenschaftlicher Bereich" signed by Schlauch on 02 December 1981 (BArch/DR3/II.Schicht/1540).

86See incomplete report without title (pp. 1, 10–13), no date, no author, in folder "Bilaterale Zusammenarbeit zwischen der DDR – Mosambique auf dem Gebiet des Bildungswesens" (BArch/DR3/II.Schicht/1539).

87See interviews; also see Dora, *Kokos*, 23. Unfortunately, sources on the way international colleagues viewed GDR personnel at the UEM were rarely found during the research period.

88See interviews with former lecturers at the UEM. In opposite to the generally positive view of the Chilean's work, a negative report was found in: "Bericht über das 1. Semester 1986 an der ABF," signed by Hunecke on 28 June 1986 (BArch/DR3/II.Schicht/1538).

end [of the project, AP] … And the Russians were kind of Latin, as well. The Bulgarians, too" [all names changed in this quote].89 Interestingly, both the Mozambican and GDR staff of this faculty partly disapproved of the leadership qualities of their Chilean colleague. But at the same time, all of them respected most of his pedagogical attitudes and teaching methods, which they perceived as being innovative and having a positive effect on students.90

### *Ideological Disputes*

The relative diversity of ideas at the UEM resulted in an, at times, ideologically contested campus. Ideological differences between Frelimo functionaries, socialist cooperators, and personnel from non-socialist countries caused sophisticated quarrels between colleagues.91 Such ideological disputes between members of the teaching staff took place on occasion, but they persisted in the Faculty of Marxism–Leninism (ML). The Faculty of ML came into existence in March 1981 and was directly subordinated to Frelimo, whereas all other faculties were affliated to the rectorate of the UEM. By June 1981, a Frelimo group started to work on a new concept for teaching ML without consulting the international staff of that faculty.92 Although GDR and Soviet teachers insisted on their interpretation of ML and tried to instill "correct" interpretations of ML philosophy into their fellow lecturers and students, their overall mission failed dramatically. Students used to mock dogmatic interpretations of ML and humorously renamed the subjects historical materialism and dialectical materialism into "hysteric and diabolic materialism."93 One Mozambican staff member mockingly compared the quality of ML teaching, concluding that "a Canadian lecturer and an East German

89Quote from interview 1, Lisbon, 2014.

90See interviews 1 and 2, Rostock, 2014; also see all interviews in Maputo, 2014.

91See all interviews, 2014.

92See report "Halbjahresbericht I/1981, Bereich Gesellschaftswissenschaften" by the GDR teaching staff at the UEM, signed by Schlauch, Maputo, 10 June 1981 (p. 7) (BArch/DR3/II.Schicht/1540).

93Quote from interview 2, Maputo, 2014.

lecturer certainly do not teach in the same way."94 Finally, in 1985, the rector asked GDR staff to make some alterations to their highly theoretical mode of teaching. To sum up, GDR lecturers of ML were openly criticized for their lack of fexibility in the application of ML to the Mozambican context. Furthermore, their focus on theory seemed unsuitable in terms of meeting the country's demand for practical answers.95 Consequently, events at the Faculty of ML fostered a rather negative perception of GDR lecturers in the feld of political and ideological education, and obligatory training in ML was abolished at the UEM.96

#### *Dialogue and Cooperative Attitude*

Besides their ineffcient ideological endeavors at the UEM, the GDR staff were largely respected for their professional knowledge in other felds, and their cooperative behavior in most aspects of collaboration was perceived well by their Mozambican partners.97 GDR cooperators usually looked to Frelimo's educational guidelines for pedagogical orientation, and a corresponding mode of conduct was offcially promoted by the GDR ministries of education (MHF and MfV) when sending staff to the UEM. GDR advisors working at the Faculty of Education, for instance, were instructed "not to copy GDR-plans" and to rather do the "necessary and right" according to Mozambican conditions.98 Bearing this in mind, GDR cooperators at the UEM proved quite open to acquiring new teaching skills proposed by their Mozambican counterparts or—in some cases—by their international colleagues.99 Beyond this, more pragmatic factors may also have played a part in the cooperative behavior of GDR staff. Documents indicate that GDR teaching staff were not always

94Quote from interview 1, Maputo, 2014.

95Lewin et al., *Die Herausbildung*, 54–55; Tullner, "Zusammenarbeit."

96Ibid., 400; also see all interviews in Maputo, 2014.

97See interviews and Voß, *Wir haben Spuren*.

98Grajek, *Berichte aus…*, 10.

99See interviews; also see Hegewald, "Berlin, Maputo."

suffciently prepared to meet the Mozambican realities on the ground, consequently, newly arrived GDR cooperators may have been more amenable to follow Frelimo guidelines.100 In addition, experienced GDR staff members were reportedly keen to maintain a high level of recognition both at the UEM101 and in relation to the Frelimo Party. Therefore, experienced staff members made some effort to effectively integrate new GDR cadres, in order to prevent losses in working standards.102

Available sources reveal a mixed view of GDR cooperators at the UEM. Retrospectively, former GDR cooperators mostly picture rather positive images of their encounters with Mozambican partners.103 Considering the GDR perspective, "*Cooperantes da RDA*" (cooperators from the GDR) were perceived as "comrades" and accordingly treated in a friendly manner.104 This affrmative view on "socialist solidarity" is congruent with the views expressed by Mozambican counterparts for the most part.105 But with reference to ideological divergences, Mozambican contemporaries were very explicit when describing the problems encountered at the faculty of Marxism-Leninism as "wars between socialist countries."106 Therefore, one can conclude that in terms of organizational tasks and teaching practices "socialist solidarity" worked well at UEM. However, in the feld of ideology some major differences between international cadres prevented such a cooperative attitude.

100See letter to the MHF "Stellungnahme der MHF-Expertengruppe Maputo zum Schreiben des Genossen Dr. Jürgen du Puits an das Ministerium für Hochund Fachschulwesen," May 1983, signed by Urbanski, Dora, Willig (BArch/DR3/ II.Schicht/1538); report "Halbjahresbericht II/1988 der MHF-Expertengruppe Maputo," 30 December 1988, signed by Dora (BArch/DR3/II.Schicht/1538).

101See report "Jahresbericht – 1981, Teilbericht der naturwissenschaftlichen und technischen Fakultät," by AG der DDR- Lehrkräfte an der UEM, Maputo, 25 November 1981, signed by Welzk (BArch/DR3/II.Schicht/1540).

102See report "Rechenschaftsbericht zur Erfüllung des Wettbewerbsprogrammes," by MHF-Expertengruppe, Gewerk- schaftsgruppe, Engenharia, Maputo, June 1987. Annex in letter of the MHF-Expertengruppe (Engenharia) to the political department of the GDR embassy in Mozambique, June 1987 (BArch/DR3/II.Schicht/1538).

103See interviews with East German *cooperantes*, and Voß, *Wir haben Spuren.*

104Grajek, *Berichte aus…*, 15.

105At this point, the limits of retrospective evaluations must be taken into consideration, because personal relations are involved here and interview partners may have been reluctant to express negative feelings about former colleagues.

106Quote from interview 2 in Maputo, 2014.

### Wind of Change and the Legacy of "Socialist Solidarity" at the UEM

In the late 1980s, changes in educational policies began to manifest, after the Frelimo government started to implement a program of "structural adjustment" as favored by their fnancial aid agencies (mainly the World Bank and International Monetary Fund). Under these circumstances, the infuence of socialist ideology in the Mozambican education system declined, as did the infuence of advisors from the GDR within the framework of the UEM. The East German model of "socialist solidarity" came to an end after the GDR's reunifcation with West Germany in 1990.107 Two years later, the Frelimo government passed a new law on education, which abstained from socialist goals in education.108

Nevertheless, educational projects realized in the framework of "socialist solidarity" seemingly supported a symbolic "Mozambicanization" of the UEM in the aftermath of independence. The history of the Faculty for Former Combatants, for instance, showed that educational ideas "borrowed"109 from socialist partners were useful for the consolidation of the new education system (SNE) and, thereby, were conducive to the decolonization process of the newly independent country in a broader sense. This faculty not only successfully promoted the education of former independence fghters within the UEM, but also qualifed a certain number of Mozambican cadres to contribute to post-colonial state building, as envisioned by the (then Socialist) Frelimo government. Although the design of the faculty combined different foreign as well as local educational concepts, in the end the integration of them all resulted in an educational institution specifc to the Mozambican context. Fittingly, the perception of the Faculty for Combatants as a Mozambican institution was highlighted by a former member of the Frelimo Central Committee (Marcelino dos Santos)

107Jude Howell, "The End of an Era: The Rise and Fall of G.D.R. Aid," *The Journal of Modern African Studies* 32, no. 2 (1994): 305–328.

108Castiano, *Bildungssystem*, 124–137; Tullner, "Zusammenarbeit," 401–405.

109For further reading on processes of "borrowing and lending" within international cooperation in the feld of education see Gita Steiner-Khamsi and Florian Waldow, *World Yearbook of Education 2012: Policy Borrowing and Lending in Education* (London/New York: Routledge, 2012).

when he stressed that within the UEM it was was "truly our faculty."110 Besides this rather symbolic interpretation of the faculty, the gradually rising number of its Mozambican teaching staff was regarded as a "Mozambicanization" process by the East German advisors at the UEM. GDR cooperators were offcially instructed to contribute to the long-term "Mozambicanization of the academic staff" at the UEM,111 and consequently GDR reports kept track of the proportion of national, in relation to foreign, cadres at the Faculty for Combatants, and regularly delivered statistical data on the faculty's staff development. Finally, in the 1984/1985 academic year, more "national" (17) than foreign (8) lecturers were reported to be teaching at the faculty. GDR cooperators perceived this parameter as an important contribution to the "Mozambicanization" of the UEM.112

The tales of everyday cooperation at the UEM exemplify how different notions of socialist education were—sometimes more and sometimes less successfully—reconciled under the overarching category of "socialist solidarity" in post-independence Mozambique. And interestingly, the overall narrative of "socialist solidarity" at the UEM points to a positive way of remembering by protagonists. This retrospective needs to be completed with further critical insight from the international staff at the UEM. Yet, for the time being, this research indicates that Mozambican counterparts perceived most acts of "socialist solidarity," delivered by East German cooperators, as rather friendly contributions to Mozambique's post-independence development.113 At the same time, the Frelimo government remained eager to channel various infows of "socialist solidarity" at the UEM toward the Party's envisioned development path. East German actors were thus infuential in the frst decade

110See "Mensagem lido pelo sr. Ermelindo Mwya em nome dos ex-alunos da Faculdade," in report on the "Semana de Educação" 13–20 April 1985, UEM, FACOTRAV, Maputo (AHM/documentation Ganhão/box 55).

111See Report "Einschätzung zum Stand und zu einigen Entwicklungen an der UEM, Bericht der MHF-Expertengruppe aus Maputo" to the MHF, Abt. Auslandskader/ Experten, Maputo, June 1986, 17 (BArch/DR3/II. Schicht/1538).

112"Informationsbericht über die Fakultät für Kämpfer und Arbeiter der Avantgarde," 1984/1985. BArch, DR3, II. Schicht, 1539, not paginated.

113In this context, it seems intriguing that three former East German cooperators have been awarded the governmental *Nachingwea Medal* for extraordinary merit many years *after* the Frelimo government's departure from a socialist path of development. See Voß and Kindler, "Um de nós," 46; Schleicher, "Spurensuche," 46.

after the country's independence when Frelimo favored socialist educational policies. But with the introduction of structural adjustment programs in the late 1980s and, related to this, the country's gradual shift toward a market-orientated, multi-party democracy, the overall standing of "socialist solidarity" at the UEM declined, with new sources of educational aid gaining importance.114

### Conclusion

My preliminary conclusion is that while the post-independence period was marked by "socialist solidarity," and the contribution East German advisors made to the construction of the frst Mozambican education system remains recognized, the effects of socialist aid on the development of higher education in Mozambique turned out to be rather sort-lived. It seems that the technical knowledge delivered by East German advisors proved to be more valuable in the long-term, as opposed to their ideological contributions on campus. To sum up, I would argue that Frelimo's attitude toward "socialist solidarity" in higher education was rather receptive, but selective. Mozambican counterparts did not always embrace East German or other foreign advice unanimously. This perceived selectivity may be illustrated by the following statement of a Mozambican university lecturer, commenting on the practice of accepting foreign aid at the UEM during the post-independence period: "You want to support us? Great! But you don't want this, you don't want that … Well, that's your problem! We will receive your suggestions … But the steering wheel is ours! In this aspect Mozambique has always been very bold."115 I fnd this self-understanding very telling, and I tend to sympathize with Mingolos' view in my interpretation of post-independence events at the UEM. Mingolo reminds us to restrain from categorizing post-colonial developments too fast into liberal or socialist developments, and encourages researchers to challenge epistemic patterns of thought related to modernity and developmentalism, since these ideas were crucial

114David N. Plank, "Aid, Debt, and the End of Sovereignty: Mozambique and Its Donors," *The Journal of Modern African Studies* 31, no. 3 (1993): 407–430; Howell, "End of an Era."

115Quote from interview 2, Maputo, 2014.

for installing the colonial systems at the beginning.116 This argument is applicable to the Mozambican case, because socialist and liberal aid agencies alike preached a rather developmentalist discourse in terms of Mozambique's higher education since independence.

### Bibliography

116Walter Mingolo, "Epistemic Disobedience and the Decolonial Option," *Transmodernity* 1, no. 2 (2011): 52.

———. "Adult Literacy and Development in Mozambique." *African Studies Review* 33, no. 3 (1990): 83–96.

———. "The Mozambican State and Education." In *Education and Social Transition in the Third World*, edited by Martin Carnoy and Joel Samoff, 275–314. Princeton/Oxford: Princeton University Press, 1990.

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**3. Conclusion**

Over the past two decades, the development of new neuroimaging techniques has produced spectacular improvements in the amount of detail with which brain activity can be monitored. As precision has rapidly been gained, though, so has the typical data set size grown steadily. The range of questions that researchers and clinicians alike have started finding an answer for with neuroimaging techniques has also dramatically expanded. All this, in turn, has created a demand for new methods of data analysis, These new methods were developed on the one hand to provide new ways to represent brain activity, and on the other hand, to make quantitative sense of the rich information embedded in very high dimensional data and to visualize them in a way that can be read and understood in a sufficiently straightforward way by researchers first and, ultimately, by clinicians.

In this chapter, we presented FH a method which effectively tackles these issues. The FH algorithm deals with the multivariate and multiscale nature of brain imaging data sets and simplifies their complexity by representing patterns in a low-dimensional space which preserves the higher dimensional information of the original pattern of connectivity. In this sense, the FH analysis may be regarded as a system-level analysis that produces a complete, holographic, representation of brain activation.

Fig. 16. The averaged Z score of number of links in the MST connecting the two clusters across subjects (N=15) for each experiment block. The two repetitive hand movements (i.e. blocks 2 and 8) resulted in higher average than the rest of the blocks. A statistical Z-test was calculated for each block with the null hypothesis that the scores in each block are a random sample from a normal distribution with mean zero. According to this test the two repetitive hand movements were found significant (p=2x10-4 and p=6.9x10-10 for blocks 2 and 8

Over the past two decades, the development of new neuroimaging techniques has produced spectacular improvements in the amount of detail with which brain activity can be monitored. As precision has rapidly been gained, though, so has the typical data set size grown steadily. The range of questions that researchers and clinicians alike have started finding an answer for with neuroimaging techniques has also dramatically expanded. All this, in turn, has created a demand for new methods of data analysis, These new methods were developed on the one hand to provide new ways to represent brain activity, and on the other hand, to make quantitative sense of the rich information embedded in very high dimensional data and to visualize them in a way that can be read and understood in a

sufficiently straightforward way by researchers first and, ultimately, by clinicians.

holographic, representation of brain activation.

In this chapter, we presented FH a method which effectively tackles these issues. The FH algorithm deals with the multivariate and multiscale nature of brain imaging data sets and simplifies their complexity by representing patterns in a low-dimensional space which preserves the higher dimensional information of the original pattern of connectivity. In this sense, the FH analysis may be regarded as a system-level analysis that produces a complete,

respectively).

**3. Conclusion**

The method also provides an effective visualization of the system, of critical importance when dealing with highly complex systems, and is particularly helpful in the identification of clusters and their hierarchies. Even more important though is the ability of the FH analysis to reveal subtle, system-level dynamical features that are hard to detect through other methods, even at the single subject level. And that might be overlooked due to prior assumptions by hypothesis-driven methods. In fact, the FH method can capture sensitive hemodynamic variations at the single block level, without further need for averaging or for contrasts between experimental conditions. In addition the method requires far less time point to localize activations than other clustering methods, viz. ICA (Bell & Sejnowski, 1995), FCA (Windischberger et al., 2003) or TCA (Zhao et al., 2007), suggesting that the FH method may play a prominent role in the development of classification algorithms for blind identification of different conditions in extremely short time series.

It is important to portray the FH method not only as an alternative but also as a valuable complement to existing methods. For instance, its dimension reduction step could be carried out using a variety of clustering techniques. Perhaps even more cogently, there is a clear complementarily between network theory and the FH method. The application of the former that we presented, i.e. the MST, clearly represents but one out of the many possible applications. To the extremely vast field of issues that network theory allows to address in a versatile but quantitatively rigorous and qualitatively explicit way, the FH method adds a compact representation in an auxiliary field that makes functional networks more explicit, as it divorces them from the anatomical space in which they live.

A distinctive quality of the FH method is represented by its versatility. While originally developed for cultured neural networks, the method can be applied to the analysis of essentially any type of signal, including the main tools for system-level neuroimaging, viz. EEG/MEG and fMRI. Although fewer examples of application to the latter are and further investigation of the method on different (viz. event-related) designs is needed, the proposed method shows great potential even for fMRI data in differentiating experimental conditions particularly when the corresponding signals are separated (Jacob et al., 2010). Since the outcome of the analysis is a holographic presentation in an abstract reduced space, it represents an ideal tool for multi-modal analysis of data from experiments combining EEG´s temporal precision with fMRI´s spatial one. Finally, the principles and implementation of the FH analysis are relatively simple and straightforward; taken together with the methods efficiency in delineating and tracking the time-varying unfolding of fine details of clustered activity at different spatial scales, it may represent a tool of election for brain scientists and for clinical neurologists alike.

## **4. Acknowledgment**

We are most thankful to Asaf Madi, Dror Kenett, Amir Rapson, Michal Kafri and Keren Rosenberg for fruitful discussions. This research has been supported in part by the Israel-US Binational Science Foundation – 2005385 (EBJ, TH), the Maguy-Glass chair in physics of complex systems (EBJ), the Tauber Family Funds and the Italy-Israel program in System Level Network Neuroscience at Tel Aviv University (EBJ), the National Science Foundation Grants PHY- 0216576 and 0225630 at UCSD (EBJ), the Israel Science Foundation - 1747/07 (TH) and by the U.S Department Of Defense W81XWH-11-2-0008 (TH).

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**7**

Xin Zhou

*P.R. China*

**Hyperpolarized Xenon Brain MRI**

*State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics,*

Since hyperpolarized 129Xe MRI was first demonstrated in the lung, air space imaging using hyperpolarized noble gases (129Xe and 3He) has progressed at a rapid rate (Goodson, 2002; Zhou, 2011c). Owing to high lipid solubility, absence of background signal in biological tissue, non-invasiveness, lack of radioactivity, different relaxation to oxygenated and deoxygenated blood, and larger chemical shift to the neighbor environment, hyperpolarized 129Xe magnetic resonance imaging (MRI) has a great potential as a tool for studying the brain, especially for

In this chapter, we will review the progress of recent research on hyperpolarized xenon brain MRI, and compare this novel technique with the conventional proton MRI in order to comment the possible innovation and development in the future. This chapter contains six

Xenon, with the chemical element symbol Xe and atomic number 54, is a member of the zero-valence elements that are called noble gases or inert gases. Xenon was discovered in the residue left over from evaporating components of liquid air by William Ramsay and Morris Travers in England in 1898, then was named by Ramsay from Greek word *ξένον*, with the meaning 'foreign' and 'strange'. Natural abundant xenon is made of nine stable isotopes, and more than 35 unstable isotopes have been characterized. Nuclei of two isotopes, 129Xe and 131Xe, have non-zero spin quantum number: 26.4% of 129Xe with a nuclear spin I=1/2 ; and 21.2% of 131Xe with a nuclear spin I=3/2 (133Xe is used as a radioisotope in nuclear medicine). These two isotopes are both detectable by NMR with sensitivities of 0.021 (129Xe, per nucleus relative to proton assuming thermal polarization) and 2.710-3 ( 131Xe). The highly enhanced signal of hyperpolarized xenon and extremely long relaxation time greatly simplified and enhanced NMR experiments, and it is the fundamental for possible

Xenon, chemically inert with the external electronic orbits fully occupied, is well known as a noble gas at room temperature and an atmospheric pressure. However, the liquid and solid

the assessment of cerebral blood flow (CBF) related to the brain function and activities.

**1. Introduction**

main parts as follows:

**2. Properties of xenon**

biological application in MRI.

*Wuhan Center for Magnetic Resonance,*

*Wuhan Institute of Physics and Mathematics, The Chinese Academy of Sciences, Wuhan,*

Strogatz, S.H. Exploring complex networks. Nature, 2001; 410: 268-76.