Intra‐household constraints on educational attainment in rural households in Papua New Guinea     

Sean Ryan  Gina Koczberski  George Nicolas Curry  Emmanuel Germis 《Asia Pacific viewpoint》2017,58(1):27-40

This paper examines intra‐household and socio‐cultural factors leading to differential outcomes in educational attainment by gender and birth order amongst smallholder oil palm households in Papua New Guinea. Not all children share equitably in the household resources allocated to education: females have lower average education levels than males, and high birth order children have higher education attainment than lower birth order siblings, indicating preferential parental investment in sons and early born children. The findings demonstrate that despite households having regular access to relatively high incomes from oil palm and residing in close proximity to schools, primary school net enrolment rates remain significantly lower than those for East Asia and the Pacific region, and the millennium development goal of universal primary education has not been met. This finding is likely to be the result of a combination of intra‐household factors including gender power imbalances, low parental education levels, the agency of youth in educational decision‐making and the weakening attraction of education as a means of improving income‐earning potential.  相似文献   

Chlorination of Channel Catfish Ponds     

Arthur C.  Potts Claude E.  Boyd 《Journal of the World Aquaculture Society》1998,29(4):432-440

Abstract— Laboratory studies with pond water samples revealed that 5 mg/L active chlorine was needed to provide enough chlorine residual to reduce biological activity. Treatment of channel catfish ponds with repeated, 0.1-mg/L doses of active chlorine from calcium hypochlorite at 6- to 8-d intervals, as sometimes done by catfish farmers, had little influence on water quality. Dissolved oxygen, total ammonia-nitrogen, and chlorophyll a concentrations and pH were similar between treated and control ponds. Concentrations of chemical oxygen demand and particulate organic matter were seldom different between treated and control ponds. Channel catfish survival and net production were not improved by chlorine treatment. Thus, chlorination of production ponds during the grow-out period is not a useful technique. Treatment of sediment samples from ponds with up to 1,200-mg active chlorinelkg soil did not reduce bacterial abundance, so chlorination of bottoms of empty ponds may not he an effective disinfection procedure. Chlorination of pond waters with 30-mg/L active chlorine caused complete kill of bacteria 24 h after treatment, although heterotrophic bacteria quickly re-populated the water. Thus, chlorination can be an effective way to disinfect ponds before stocking.  相似文献   

Rapid remote recognition of habitat changes     

Arthur P. Cracknell 《Preventive veterinary medicine》1991,11(3-4):315-323

An attempt is made to give a realistic appraisal of the possibilities and shortcomings of remote sensing techniques in the context of detecting habitat changes.

Consideration has to be given to the various spatial scales at which remote sensing data are exploited, and to the relationship between the size of the object of an investigation and the intrinsic limitations on the ground resolution (instantaneous field of view, IFOV) of the detecting system. Features larger than the IFOV are commonly studied and, in certain circumstances, features that are smaller than the IFOV can also be detected. However, the question of obtaining information about objects or features that are very small compared with the IFOV is much more difficult. Examples include sheep distribution, locust prediction and the development of toxic algal blooms at sea. The monitoring of blooms, once they have begun to appear, is now feasible. However, it is much more difficult to study the conditions leading to the development of blooms and to give advance warning of their growth. The study of this type of problem is still in its infancy.

The other question that has to be addressed concerns the timeliness of the extraction of information from remotely sensed data. With the exception of the meteorological community, the philosophy for the last decade or two has been simply to capture remotely sensed data from satellites, to archive it on magnetic tape and to hope that someone, somewhere, someday, will retrieve the data from the archive, analyse it and possibly make use of it. In many applications of remotely sensed data, such as oil pollution monitoring, agricultural yield prediction, and epidemic and plague prevention, the remotely sensed data must be analysed, interpreted and the results distributed to the end users in something approaching real time. It is pointless, other than as an academic exercise, to predict a plague or epidemic 5 years after it has happened!  相似文献   

The conformation of wheat gluten proteins. The secondary structures and thermal stabilities of α-, β-, γ- and ω-Gliadins     

Arthur S. Tatham  Peter R. Shewry 《Journal of Cereal Science》1985,3(2):103-113

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Evaluation of maternal parent and puroindoline allele on kernel texture in a reciprocal cross between two hard spring wheat cultivars     

Kristene R. Gedye  Arthur D. Bettge  Garrison E. King  Craig F. Morris 《Euphytica》2005,141(1-2):121-127

Kernel texture is an important characteristic for both the milling and the end-use quality of wheat (Triticum aestivum L.). Gene sequence variation and mutations to the two puroindoline genes (Pina and Pinb), located at the Ha locus on chromosome 5DS, account for the majority of variation in wheat kernel texture. Other factors also influence kernel texture, including effects associated with different maternal parent backgrounds. To investigate the effect of two hard puroindoline alleles in different maternal backgrounds, a population of 228 recombinant inbred lines (RILs) derived from a reciprocal cross between two wheat cultivars ID377s (Pina-D1b/Pinb-D1a) and Klasic (Pina-D1a/Pinb-D1b) were examined in two succeeding generations (F₇ & F₈). Kernel texture was determined using the Single Kernel Characterization System (SKCS) and the RIL puroindoline haplotype was identified by the sequence-specific PCR amplification of each gene. Analysis of variance identified a significant (P 0.001) effect of the maternal parent and puroindoline mutation on kernel texture. RILs containing the Pina-D1b mutation were significantly harder than lines containing the Pinb-D1b mutation. RILs which had Klasic as the maternal parent were significantly harder than those which had ID377s as the maternal parent. When the maternal parent and puroindoline allele were analyzed in combination, RILs derived from Klasic as the maternal parent and the Pina-D1b allele were significantly harder (P 0.001) than those containing the same allele but ID377s as the maternal parent. The same occurred for RILs containing the Pinb-D1b allele, lines with Klasic as the maternal parent were harder than lines with ID377s as the maternal parent. These results corroborate the harder phenotype of the Pina-D1b allele and indicate a significant maternally-inherited contribution to kernel texture variation.  相似文献   

An Assessment of Variation for Nutritional and Non-nutritional Carbohydrates in Lentil Seeds (Lens culinaris)   总被引：1，自引：0，他引：1  

J. Frias    C. Vidal-Valverde  A. Bakhsh    A. E. Arthur  C. Hedley 《Plant Breeding》1994,113(2):170-173

The levels of the raffinose family of α-galactosides (raffinose, stachyose, verbascose and ciceritol) and of the nutritional carbohydrates (fructose, sucrose and starch) were determined in the seed of a range of lentil lines from germplasm collections and commercial Spanish cultivars. Significant levels of variation were found for all the measured characters, and particularly for the α-galactosides. The greatest variation was found in verbascose content, which ranged from about 1 % of the seed dry weight to undetectable amounts. The relationship between these chemical components and morphological seed characteristics was assessed. The only significant relationship between the different groups of characteristics was a positive correlation between the level of verbascose and the average seed weight for each genotype.  相似文献   

Genetical studies of quantitative characters in peas. 1. A seven-parent diallel cross of cultivars     

Brian Snoad  A. E. Arthur 《Euphytica》1973,22(2):327-337

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Herbicides in war: Current status and future doubt     

Arthur H. Westing 《Biological conservation》1972

The US anti-plant aerial chemical warfare programme in South Vietnam and its effects are described. Between 1961 and 1971, the US, in its forest cover denial programme, expended over 49 million kilograms of herbicides on 2 million hectares of forest lands, and in its food denial programme expended over 3 million kilograms on 300 thousand hectares of croplands. Major herbicides used against forests were 2,4-D (26 million kg), 2,4,5-T (22 million kg), and Picloram (1·5 million kg), while against agricultural fields were used over 3 million kg of dimethylarsinic acid. About 15 per cent of the area of South Vietnam's forests have been sprayed once, and an additional 4 per cent have been sprayed.multiply; about 8 per cent of croplands have been strayed. In the areas that have been sprayed there have been alteration and simplification of the plant and animal communities, a loss of mineral nutrients, acceleration of erosion in hilly terrain, and reduction in ecosystem productivity. Restoration time in the once-sprayed areas is expected to exceed one decade, and, in the multiply-sprayed areas, several decades. Approximately 0·5 million hectares have been utterly devastated. It is estimated that food was destroyed that would have sufficed to supply the total diets for one full year of 894,900 Vietnamese (largely civilian). The herbicides have directly or indirectly resulted in various medical and veterinary problems. Timber losses have been estimated to total 47 million cubic meters.  相似文献   

Climate change and forest decline: A review of the red spruce case     

Edward R. Cook  Arthur H. Johnson 《Water, air, and soil pollution》1989,48(1-2):127-140

Climate change as a contributor to the decline of red spruce is investigated. Previous climatic response model results are reviewed and more detailed time-dependent modeling of tree growth-climate interactions are performed using the Kalman filter. These new results show that there is a clear temporal and elevational dependence in the response of red spruce to climate. Influence of abnormally warm prior-August temperatures become increasingly time-dependent with decreasing elevation, which is contrary to the elevational gradient in the severity of decline. Thus, this variable, which had been implicated in red spruce declines from previous studies, is unlikely to be a primary cause of the current decline. However, it may be implicated in earlier declines at low elevations. Prior-December temperatures are influential at all elevations, but time-dependent only at the highest elevational zone. The emergence of a strongly time-dependent prior-November temperature response is clearly associated with a time-trend in the temperature record. Thus, it is likely that red spruce is responding, in a transient sense, to changing climate. An additional transient response to current-July temperatures is not associated with any unusual behavior in the data and is, as yet, unexplained. These results show that red spruce is not in equilibrium with its climatic environment, which may have made it more susceptible to damage caused by natural and anthropogenic factors.  相似文献   

Book reviews     

K. C. Pillai  B. Z. Siegel  S. M. Siegel  A. S. Kallend  Elmer Robinson  Arthur C. Stern 《Water, air, and soil pollution》1987,32(3-4):461-461

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