Rural change and nature conservation in Africa: A case study from Swaziland

High population growth and deteriorating economic conditions imperil Africa's natural environment. Conservationists are trying to cope with the threat by working in rural communities. Yet it is unclear whether they can be effective when social and economic change in rural areas is so rapid. Northeast Swaziland provides a case study. The landscape has been transformed since the 1950s, and conservationists are the only people now giving nature conservation a high priority. Land uses incompatible with local nature reserves are supported because they provide jobs. Thus, conservationists find themselves facing a world where wildlife is increasingly devalued as the forces of change accelerate. This paper concludes: (1) conservationists must expand their influence into rural communities, (2) an integrated development and conservation plan is required for northeastern Swaziland, and (3) only the alleviation of poverty will secure the future of nature conservation in Swaziland as well as the rest of Africa.     

Realities in breed improvement programmes for dairy goats in East and Central Africa

Increasing population pressure, land scarcity and diminishing production resources are promoting goat production in the tropics. Dairy goat breeding (DGB) projects have been implemented by development agencies, governments and the private sector with the objective of improving the dairy merits genetically through crossbreeding with exotic genotypes. The performance of these projects is still a cause for concern. Therefore, sustainable dairy goat breeding forces various stakeholders to re-orient their breeding goals, strategies and design of breeding programmes towards a sustainability perspective. This paper highlights a set of key requirements for establishing sustainable dairy goat breeding programmes. Conclusions are drawn based on the lessons learnt from numerous examples of DGB projects in East and Central Africa keeping sustainability concerns insight to inform on-going and future projects.     

Vegetation dynamics in central Africa since 18,000 yr BP: pollen records from the interlacustrine highlands of Burundi, Rwanda and western Uganda

A standardized analysis of palaeoecological data, in the form of six pollen sequences and forty- four radiocarbon ages, has permitted a region-wide reconstruction of Late Quaternary vegetation dynamics for the interlacustrine highlands of central Africa.
A landscape widely dominated by ericaceous scrub and grasslands, but also supporting sparse patches of open-canopied montane forest, possibly in those areas with a topography most favourable to the growth of trees, is indicated for the last glacial maximum of 18,000 yr bp . Major expansions in the extent of upper altitudinal forms of montane forest occurred from around 12,500 yr bp , while lower moist montane forest—the expected climax for much of the region today—did not become prominent until 11,000 yr bp to 10,000 yr bp . From the palaeoecological evidence at least, it appears that the major east Central forest refuge, proposed by some workers on the basis of current species' distribution patterns, did not extend to the eastern flanks of the Albertine Rift.
A late glacial–early Holocene transition is only fully chronicled in two of the sites. However, it appears that the expansion of lower montane forest had a time-transgressive pattern across the region, and was not simply from low to high altitude. The composition of forests during the early Holocene appears to have been different to that in the later stages of the present interglacial, as taxa presently associated with wetter and/or more open forest types were much more common. Pollen data also indicate that higher altitude parts of the interlacustrine highlands were more attractive to the earliest (possibly Bantu-speaking) farmers and metal-workers. There is evidence of wide-spread forest clearance around the beginning of the present millennium, possibly as a result of substantial changes in socio-economic conditions, and patterns of settlement, associated with the onset of the Late Iron Age.     

Sibling similarity in development of covariation among physical traits in early childhood

We studied the sibling similarity in development of covariation among body size characters (body weight (W), body length (S) and head circumference (HC) in Tel Aviv infants from birth up to 2 years of age. We investigated the effects of parental geographic origin, profession, age, current residence, and of family size. Multiple regression analysis with "dummy" procedure established that none of these variables had any significant effect on the aforementioned anthropometric traits. The matrices of phenotypic and genetic correlations, based on sibling similarity data, among age-specific W, S, and HC (measured for 12 different ages) were subjected to principal component analysis in order to elucidate patterns over the age groups. The patterns of both analyses, phenotypic and genetic, were quite similar: one factor in each (first genetic and second phenotypic) had a high positive correlation with early, first 2-3 months of life, W, S, and HC. Three other extracted factors correlated strongly, each with late W, S, and HC, respectively. The results of additional principal component analyses of age-specific W, S, and HC matrices separately, indicate the possibility of existence of two genetic subsystems, the first determining early postnatal stages of human ontogeny, and the second, later phases of child development.     

Effect of Weaning on Small Intestinal Structure and Function in the Piglet

Fifty-four piglets were selected from 12 litters weaned at 17 (Treatment 1), 21 (Treatment 2), 28 (Treatment 3) and 35 (Treatment 4) days old, respectively, to determine the effect of weaning age on small intestinal villus morphology, immunology and histochemistry. From proximal duodenum, proximal jejunum, distal jejunum and middle ileum, intestinal samples with three replicates (piglets) in each treatment were taken at 18, 22, 28 and 36; 22, 28, 36 and 43; 28, 36, 43, and 50; and 18, 22, 28, 36, 43 and 50d of age in Treatment 1, 2, 3 and 4, respectively. This was equivalent to 12h, 3d, 1 week, 2 week postweaning in Treatment 1; 12h, 1 week, 2 week, 3 week postweaning in Treatment 2 and 3, and all the same age in Treatment 4 as in Treatment 1, 2, 3, respectively. The results showed that villous height of duodenum and proximal jejunum decreased significantly in Treatment 1 and 3. Crypt depth in the duodenum, proximal jejunum and ileum also decreased significantly in Treatment 1. Date had significant effect on villous height of the duodenum, distal jejunum and ileum with the shortest on day 29 and crypt depth of all positions increased with piglet age except the crypt depth in proximal jejunum decreased on day 50. Weaning age and day of age had significant effects on intraepithelial lymphocyte (IEL) number and goblet cell (GC) number at all positions of small intestinal mucosa in piglets. The number of IEL at all segments of small intestinal mucosa in Treatment 3 increased significantly compared to those in other treatments, but IEL number at all locations of small intestinal mucosa in Treatment 2 decreased significantly compared to those in other treatments. The number of GC in small intestinal mucosa increased significantly in early-weaned (< day 21) piglets. It appears that providing fluid milk replacer for a few days postweaning could dramatically reduce the negative impact of weaning on villous morphology and digestive and absorptive function, especially in pigs weaned prior to 3 week of age. Finally, as weaning age was reduced, GC had a greater role in intestinal duct protection.     

Demography of the Hadza, an increasing and high density population of Savanna foragers.

This is a report on the demography of the Hadza, a population of East African hunter-gatherers. In it, we describe the results of a census, and our estimation of age structure, survivorship, mean age of women at childbearing, number of live children, total population size and density, and rate of change since 1967. We show that relevant measures fit closely the stable population model North 6 chosen by Dyson to represent Hadza demography in the 1960s. We compare aspects of Hadza demography with surrounding non-Hadza and with the !Kung. Among other things, we find that the Hadza have a higher population density, higher fertility, and a faster population growth rate than do the !Kung. These demographic differences are consistent with our expectations, which were based on differences in the costs and benefits of foraging in the two regions. We also show that Hadza demographic parameters display remarkable consistency over the past 20 years. Since neighboring populations have been encroaching on the area used by the Hadza, and Hadza foragers have been subject to interludes of externally imposed settlement, this consistency is surprising. We discuss some of the implications.     

The past, present and future of childhood malaria mortality in Africa

During the past few years, there has been a historic series of declarations of renewed commitment to malaria control in Africa. Whether the burden of malaria is increasing in Africa is a moot point. This article attempts to re-construct the evidence for the trends in childhood mortality as a result of Plasmodium falciparum infection over the last century in Africa.     

Creating Grasslands: Social Institutions and Environmental Change in Mkambati Area, South Africa

Through a case study of the grassland system of the Mkambati area in the Eastern Cape, South Africa, the paper explores the interaction of social institutions and ecological processes in the creation of a diverse grassland environment. A number of different transitions between grassland states are examined in detail, highlighting a range of social and institutional factors influencing grassland change. The spatial patterning of different grassland types and the frequency of transitions between them are shown to be dependent on the institutional relationships between different social actors. Understanding such complex and multifaceted processes of environmental change requires analytical tools which combine social and ecological perspectives;an extended form of qualitative state-transition modeling, which incorporates institutional dimensions, is therefore explored.     

Genetic diversity,evolutionary history and implications for conservation of the lion (Panthera leo) in West and Central Africa

Aim In recent decades there has been a marked decline in the numbers of African lions (Panthera leo), especially in West Africa where the species is regionally endangered. Based on the climatological history of western Africa, we hypothesize that West and Central African lions have a unique evolutionary history, which is reflected by their genetic makeup. Location Sub‐Saharan Africa and India, with special focus on West and Central Africa. Method In this study 126 samples, throughout the lion’s complete geographic range, were subjected to phylogenetic analyses. DNA sequences of a mitochondrial region, containing cytochrome b, tRNAPro, tRNAThr and the left part of the control region, were analysed. Results Bayesian, maximum likelihood and maximum parsimony analyses consistently showed a distinction between lions from West and Central Africa and lions from southern and East Africa. West and Central African lions are more closely related to Asiatic lions than to the southern and East African lions. This can be explained by a Pleistocene extinction and subsequent recolonization of West Africa from refugia in the Middle East. This is further supported by the fact that the West and Central African clade shows relatively little genetic diversity and is therefore thought to be an evolutionarily young clade. Main conclusions The taxonomic division between an African and an Asian subspecies does not fully reflect the overall genetic diversity within lions. In order to conserve genetic diversity within the species, genetically distinct lineages should be prioritized. Understanding the geographic pattern of genetic diversity is key to developing conservation strategies, both for in situ management and for breeding of captive stocks.     

Folk conceptualizations of racism and antiracism in Brazil and South Africa

Abstract

Folk conceptualizations of racism can be defined as ordinary people's understandings of the sources and persistence of racism. They function as equalization strategies – by denying the legitimacy of racism – and guide beliefs regarding antiracism strategies. I explore folk explanations of racism among black professionals in Brazil and South Africa by drawing on sixty interviews with members of these groups. In Brazil, racism is understood as an historical lingering, a product of ignorance, which will disappear with time and education. In South Africa, racism is viewed as more resilient, as a part of human nature and as a consequence of the competition for resources. These explanations of racism are closely related to the antiracism narratives that are salient in these two contexts: while Brazilian respondents affirm their belief in racial mixture and moral education, South African respondents are more uncertain about the possibilities of weaker racial boundaries in their country, relying on institutional constraints as their main antiracism strategy.     

The effects of residential locality on parental and alloparental investment among the Aka foragers of the central African Republic

In this paper I examine the intracultural variability of parental and alloparental caregiving among the Aka foragers of the Central African Republic. It has been suggested that maternal kin offer higher frequencies of allocare than paternal kin and that maternal investment in infants will decrease when alloparental assistance is provided. Behavioral observations were conducted on 15 eight- to twelve-monthold infants. The practice of brideservice and the flexibility of Aka residence patterns offered a means to test the effect of maternal residence on parental and alloparental investment. There was significant variation in the frequency of investment and who supplied care to infants depending on whether mothers resided with their kin or their husbands’ kin. However, in spite of the variation in allocare, when all categories of caregivers were examined collectively, infants received similar overall levels of care. Courtney L. Meehan is a Ph.D. student in cultural anthropology at Washington State University. Her research interests include parenting, alloparenting, female social networks, and female-female cooperation and competition.     

机械通气新生儿撤机失败的危险因素分析及预防对策探讨

摘要 目的：分析机械通气新生儿撤机失败的危险因素,并探讨预防对策。方法：回顾性选取2018年4月~2021年3月在我院接受机械通气治疗的256例新生儿的临床资料。根据是否发生撤机失败将患儿分为撤机成功组与撤机失败组。撤机失败的影响因素采用单因素及多因素Logistic回归分析,并探讨预防对策。结果：256例接受机械通气的新生儿中,有29例发生撤机失败,撤机失败率为11.33%。单因素分析结果显示：撤机成功组与撤机失败组在胎龄、出生体重、Apgar评分、产伤情况、呼吸机相关性肺炎、多脏器功能损害、肺部感染、败血症、营养支持、撤机时血氧分压（PO₂）、撤机时心率、撤机时二氧化碳分压（PCO₂）方面对比差异有统计学意义（P<0.05）。多因素Logistic回归分析结果显示：撤机时PO₂偏低、撤机时心率较高、撤机时PCO₂较高、多脏器功能损害、无营养支持、伴有肺部感染、发生呼吸机相关性肺炎、胎龄＜37周是导致机械通气新生儿撤机失败的危险因素（P<0.05）。结论：导致机械通气新生儿撤机失败的危险因素较多,临床应针对危险因素进行干预,并在撤机前进行充分评估以减少撤机失败率。     

Isolation and the origin of the khoisan: Late pleistocene and early holocene human evolution at the southern end of Africa

The debate between the proponents of the Recent African Origin and the Multiregional Evolution models for the origin of anatomically modern humans has not been of great importance to the interpretation of late Pleistocene human fossils in South Africa. The main reason is that both models propose that evidence of anatomically moderns should happen in South Africa at an early date. A more important issue to the African context is whether or not those early transitions to modernity were accompanied by the development of the distinctive local populations known today as the Khoisan. Serogenetic evidence suggests a relative antiquity for the origins of living Khoisan peoples, but this may simply reflect the longer time that anatomically modern peoples have lived in the sub-continent. A search for features of distinctive Khoisan morphology in the early remains may be of more value as it might indicate the presence of a local adaptive pattern to the special environment conditions of the region.     

Involvement of the central melanocortin system in the effects of caffeine on anxiety-like behavior in mice

Aims

To investigate the role of the melanocortin (MC) system in the framework of the central nucleus of the amygdala (CeA) in the differential effects of the adenosine receptor blocker caffeine on anxiety-like behavior, using the social interaction (SI) test.

Main methods

Caffeine was injected intraperitoneally, alone or in combination with alpha-melanocyte stimulating hormone (α-MSH), the MC4 receptor agonist RO27-3225 or the antagonist HS014 via the intra-CeA route. The effects of chronic (21 days) caffeine, given alone or concurrently with α-MSH, or RO27-3225, were investigated. The effects of withdrawal of these treatments on SI time were also evaluated. Furthermore, the acute effects of HS014 were investigated in different sets of caffeine-withdrawn mice.

Key findings

Acute injection of caffeine, RO27-3225, or α-MSH produced anxiety-like behavior. Prior treatment with α-MSH, or RO27-3225 potentiated the caffeine-induced anxiety-like behavior. Subchronic treatment with HS014 increased the SI time, which was attenuated by caffeine. Chronic administration of caffeine resulted in tolerance to caffeine's anxiogenic effect, while abrupt discontinuation of the treatment produced peak anxiety-like behavior at 72 h post-withdrawal. Concurrent administration of α-MSH, or RO27-3225 with chronic caffeine delayed the development of tolerance and prevented withdrawal-induced anxiety-like behavior. Moreover, acute treatment with HS014 at 72 h post-withdrawal attenuated the anxiety-like behavior.

Significance

α-MSH, possibly via MC4 receptor in the neuroanatomical framework of the CeA, may contribute to the acute, chronic and withdrawal actions of caffeine associated with anxiety-like behavior in the neuroanatomical framework of the CeA.     

Proprioceptive reflex interactions with central motor rhythms in the isolated thoracic ganglion of the shore crab

Summary Experiments were carried out on an isolated central nervous system preparation of the shore crab,Carcinus maenas, comprising the fused thoracic ganglion complex with two proprioceptors of one back leg still attached. These, the thoracic-coxal muscle receptor organ and the coxo-basal chordotonal organ, monitor movement and position of the first and second joints, respectively. Motor activity was recorded extracellularly from the central cut ends of the nerves innervating the promotor and remotor muscles of the thoracic-coxal joint, and the levator and depressor muscles of the coxal-basal joint of the same leg. Simultaneous intracellular recordings were made from central processes of individual motoneurones of each muscle.In the absence of any sensory input, the isolated ganglion exhibited rhythmic bursting in the motor nerve roots, with a slow, usually irregular cycle period of 5–50 s.Both receptor organs had both intra-joint and inter-joint effects on the rhythmically active preparation. In most cases the coxo-basal receptor organ had the greater effect.Resistance reflexes initiated by each of the joint proprioceptors were modulated by the rhythmic activity.It may be concluded that, while the isolated thoracic ganglion of the crab is capable of generating rhythmic motor output, proprioceptive feedback from the two basal joints is important in shaping the motor patterns underlying locomotion. Inappropriate reflexes which would impede active movements about these joints are modulated or reversed so as to permit and even reinforce intended locomotory movements.     

Assessing species occurrence and species‐specific use patterns of bais (forest clearings) in Central Africa with camera traps

The impacts of increasing resource extraction on biodiversity in the Central African rainforest are largely unknown, in part due to the lack of baseline data on species occurrence across the basin. Natural forest clearings (bais) in this region are key habitats for a variety of vertebrates and offer opportunities for monitoring species distribution. Information on species composition, however, is lacking from the majority of areas (except for long‐term study sites). Approaches and protocols for short‐term bai assessments can greatly advance such baseline knowledge. This study demonstrates that camera traps provide an effective method for species inventories (species occurrence and temporal activity patterns) and monitoring at bais across the broader region. In comparison with direct observational studies, they performed especially well regarding rare and nocturnal species. Camera traps during sampling sessions of 4 weeks or less recorded previously undocumented, and 65–94% of the mammals known to use each of seven Central African bais. Results indicate that many mammal species, in particular African forest elephants (Loxodonta africana cyclotis), visit bais preferentially at night. This underlines the urgent need for monitoring tools providing both diurnal and nocturnal data to provide baseline data that address conservation and management objectives.