Understanding women’s burdens: preliminary findings on psychosocial health among datoga and iraqw women of northern tanzania

This preliminary, community-based study examines major stressors identified by Iraqw and Datoga women of Mbulu District, Tanzania, and describes steps in creating a culturally specific questionnaire to assess mental health burdens. This area of Tanzania is remote, with limited access to goods and services, and is undergoing dramatic social and economic changes. Iraqw and Datoga reside in close proximity and often intermarry but have different cultural and subsistence responses to this rapid social change. Data were collected from May to October 2002, with 49 Datoga women and 64 Iraqw women interviewed. In-home interviews were conducted to have women (1) free-list their primary concerns and (2) answer questions from a translated (in Datoga and Iraqw) and modified standardized mental health questionnaire. Both groups of women identified hunger, the lack of animals, particularly cattle, and health/illnesses as the most common major stressors. Other frequently cited stressors included crop failure, general fears of violence, paying taxes, and no money for basic needs. Additional refinements are required for the mental health questionnaire, with strengths and limitations discussed. Such data, while preliminary, augment efforts to analyze the emotional burdens associated with dramatic social change.     

Determining the Causes of Spatial and Temporal Variability of Wheat Yields at Sub-field Scale Using a New Method of Upscaling a Crop Model

Wheat yields in the Mediterranean climate of Western and Southern Australia are often limited by water. Our measurements on a 70 ha growers field showed linear relationships between grain yield and the plant available soil water storage capacity (PAWc) of the top 100 cm of the soil profile. PAWc was linearly related to apparent soil electrical conductivity measured by proximal sensing using electromagnetic induction (EM38). The APSIM wheat model also employs PAWc as one of the systems parameters and simulated linear relationships between PAWc and yield. These relationships were used to transform an EM38-derived PAWc map of the field into yield maps for three major season types (dry, medium and wet) and nitrogen (N) fertiliser management scenarios. The results indicated that the main cause of temporal and spatial yield variability within the field was due to interactions of seasonal rainfall, PAWc and N fertiliser applications. Spatial variability was low in low rainfall years when yields across the field were low and the higher soil water storage capacity sites were often underutilised. With adequate N, spatial variability increased with seasonal rainfall as sites with higher PAWc conserved more water in wet seasons to give higher yield response than sites with low PAWc. The higher yield response of high PAWc sites to rainfall gave rise to larger temporal variability compared with sites with low PAWc. Provision of adequate N is required for the water limited yield potential to be expressed and this increased both spatial and temporal variability. Sites with low PAWc performed poorly irrespective of rainfall and N application. PAWc is inherently low on deep coarse sands; these sites should be considered for a change in land use. Elsewhere, strategic management interventions should aim to improve PAWc through sub-soil amelioration and deep root growth to increase the capital asset of the farm. The resulting increase in yields will occur in favourable seasons and with adequate fertiliser provisions. The largest grain yield response to water and N will be obtained on sites with the highest PAWc and it is at those sites that the greatest profits from fertiliser use could be achieved in wet seasons.     

Unbalanced ranked set sampling for estimating a population proportion

The application of ranked set sampling (RSS) techniques to data from a dichotomous population is currently an active research topic, and it has been shown that balanced RSS leads to improvement in precision over simple random sampling (SRS) for estimation of a population proportion. Balanced RSS, however, is not in general optimal in terms of variance reduction for this setting. The objective of this article is to investigate the application of unbalanced RSS in estimation of a population proportion under perfect ranking, where the probabilities of success for the order statistics are functions of the underlying population proportion. In particular, the Neyman allocation, which assigns sample units for each order statistic proportionally to its standard deviation, is shown to be optimal in the sense that it leads to minimum variance within the class of RSS estimators that are simple averages of the means of the order statistics. We also use a substantial data set, the National Health and Nutrition Examination Survey III (NHANES III) data, to demonstrate the feasibility and benefits of Neyman allocation in RSS for binary variables.     

Variable Rate Application of Nematicides on Cotton Fields: A Promising Site-Specific Management Strategy

Field tests were conducted to determine if differences in response to nematicide application (i.e., root-knot nematode (RKN) populations, cotton yield, and profitability) occurred among RKN management zones (MZ). The MZ were delineated using fuzzy clustering of five terrain (TR) and edaphic (ED) field features related to soil texture: apparent soil electrical conductivity shallow (EC_a-shallow) and deep (EC_a-deep), elevation (EL), slope (SL), and changes in bare soil reflectance. Zones with lowest mean values of EC_{a- shallow}, EC_{a- deep}, NDVI, and SL were designated as at greater risk for high RKN levels. Nematicide-treated plots (4 rows wide and 30 m long) were established in a randomized complete block design within each zone, but the number of replications in each zone varied from four to six depending on the size of the zone.The nematicides aldicarb (Temik 15 G) and 1,3-dichloropropene (1,3-D,Telone II) were applied at two rates (0.51 and 1.0 kg a.i./ha for aldicarb, and 33.1 and 66.2 kg a.i./ha for 1,3-D) to RKN MZ in commercial fields between 2007 and 2009. A consolidated analysis over the entire season showed that regardless of the zone, there were not differences between aldicarb rates and 1,3-D rates. The result across zones showed that 1,3-D provided better RKN control than did aldicarb in zones with low EC_a values (high RKN risk zones exhibiting more coarse-textured sandy soils). In contrast, in low risk zones with relatively higher EC_a values (heavier textured soil), the effects of 1,3-D and aldicarb were equal and application of any of the treatments provided sufficient control. In low RKN risk zones, a farmer would often have lost money if a high rate of 1,3-D was applied. This study showed that the effect of nematicide type and rate on RKN control and cotton yield varied across management zones (MZ) with the most expensive treatment likely to provide economic benefit only in zones with coarser soil texture. This study demonstrates the value of site specific application of nematicides based on management zones, although this approach might not be economically beneficial in fields with little variability in soil texture.     

Can Carbon and Phosphorous Amendments Increase Native Forbs in a Restoration Process? A Case Study in the Northern Tall‐grass Prairie (U.S.A.)

In the northern Great Plains (United States), sites with less than 20% of native species are difficult to restore. We have experimented with a restoration method that shows some promise. It consists of systematically installing simulated small‐scale patches (8.0 m² in size) over 25% of an old field and then seeding these patches with native species. The working hypothesis is that these patches will generate a constant source of propagules which in time will lead to increases in native species diversity within the surrounding grass matrix. The objective of this paper was to determine whether soil amendments should be used to facilitate the establishment and persistence of native species (primarily forbs) within these patches. We seeded the patches with a mixture of native grass and forb species and applied four soil treatments: P fertilization, C additions, C + P, and a control (no amendments). Results for the first 5 years were as follows: (1) seeded forb richness was mostly unaffected by soil amendments; (2) seeded and nonseeded forb biomass and density were substantially reduced by C additions, whereas they were unaffected or increased under P additions; (3) both seeded and non‐native grass biomass substantially increased with C additions; and (4) there was an inverse relationship between native seeded forbs and non‐native grass biomass. Our conclusions are that: (1) P amendments are a potential tool for enhancing native seeded forb biomass in simulated small‐scale disturbance patches; and (2) C additions, although enhancing seeded grass biomass do not reduce the biomass of non‐native grasses.     

PBL 法应用于留学生精神科临床教学中的体会与总结

随着医学教育的革新,PBL(Problem-based Learning)作为以问题为基础、学生为中心、培养学生自主学习能力的一种新型教学模式,逐渐成为国际现代医学教学改革的核心。本文在简单介绍PBL教学模式的衍生发展的基础上,结合笔者几年来的留学生教学经验和目前留学生教学的现状,阐述了在留学生精神病学教学中开展PBL教学的必要性,进而提出了适合留学生教学的PBL教学具体方案。     

Effect of trap design, trap size and pheromone dose on male capture of two pine bast scales species (Hemiptera: Matsucoccidae): implications for monitoring and mass-trapping

Abstract 1 The effects of pheromone dose, trap size and trap design on the capture of male Matsucoccus feytaudi were studied in maritime pine forests of Portugal, France and Italy, and Matsucoccus josephi in Aleppo pine stands of Israel. 2 Males of both species respond to racemic mixtures of the respective sex pheromone at a dosage as low as 25 µg. However, for low population densities of M. feytaudi, a 50 µg dosage was needed to guarantee male catches significantly different from the control trap. 3 Male capture increased with increasing dosage up to a threshold level for both species. Overdose repellence was not observed even with baits containing 1600 and 2200 µg of the pheromone of M. josephi and M. feytaudi, respectively. 4 For M. feytaudi, a higher dose–response was observed at medium population densities, whereas lesser captures were registered at low and high population densities, suggesting female competition in the latter case. 5 Catches of M. feytaudi males were not affected by trap design, whereas M. josephi males were caught in significantly greater numbers in delta traps. Large traps caught significantly more males of both species. 6 The relative higher male catches in the marginal zone of the sticky traps is probably related to males landing behaviour in the vicinity of the pheromone source. 7 The shape and size of the trap did not affect the bias of the estimates of male catches. However, the plate traps provided higher precision. Both bias and precision improved with increasing dose.     

A comparison of cDNA, oligonucleotide, and Affymetrix GeneChip gene expression microarray platforms.

We have conducted a study to compare the variability in measured gene expression levels associated with three types of microarray platforms. Total RNA samples were obtained from liver tissue of four male mice, two each from inbred strains A/J and C57BL/6J. The same four samples were assayed on Affymetrix Mouse Genome Expression Set 430 GeneChips (MOE430A and MOE430B), spotted cDNA microarrays, and spotted oligonucleotide microarrays using eight arrays of each type. Variances associated with measurement error were observed to be comparable across all microarray platforms. The MOE430A GeneChips and cDNA arrays had higher precision across technical replicates than the MOE430B GeneChips and oligonucleotide arrays. The Affymetrix platform showed the greatest range in the magnitude of expression levels followed by the oligonucleotide arrays. We observed good concordance in both estimated expression level and statistical significance of common genes between the Affymetrix MOE430A GeneChip and the oligonucleotide arrays. Despite their apparently high precision, cDNA arrays showed poor concordance with other platforms.     

The problem of precision and trend detection posed by small elephant populations in West Africa

The precision of elephant estimates from aerial sample surveys and dung counts is inversely proportional to abundance. West African elephant populations are already small, and the power of a monitoring programme to detect changes in abundance diminishes as the population shrinks in size. Thus it will be difficult to evaluate the effects on elephant numbers of new management policies in West Africa. The same will be true of monitoring schemes for antelope and primate populations that are hunted for bushmeat. Elephant estimates from dung counts are more precise than those from aerial sample surveys, and changes in elephant numbers are more likely to be detected in the subregion by dung counts than by aerial sample surveys.