中国生猪生产耗水及影响因素分析

随着城市化的发展和人均收入的提高,中国居民对猪肉的需求日益增长。猪肉生产耗水量大,其包括饲料作物生长所消耗的水,也包括生猪生产过程所消耗的水。本文从生猪生产的角度计算了2001-2012年生猪生产耗水,结果表明生猪生产水足迹由2001年的3.39m³/kg下降到2012年的3.31m³/kg,但生猪生产耗水却从2001年的1 910亿m³上升到2012年的2 650亿m³,增长了38.95%。运用对数平均迪氏指数法（Logarithmic Mean Divisia Index,LMDI）对影响生猪生产耗水的因素进行了分析。在影响生猪生产耗水的3个因素中,人口的增长和猪肉消费量的增加导致生猪生产耗水的增加,而生猪生产水足迹的降低则会降低生猪生产耗水,三者中,猪肉消费量对生猪生产耗水的贡献最大。同时,农场耗水所占比例不断增加。本研究第一次揭示了长时间尺度,中国大、中、小规模化及散养养殖情况下,生猪生产水足迹的变化以及生产耗水。这有助于处理中国生猪产业的快速发展和耗水量不断增加的关系,促进生猪产业的可持续发展。     

Detection of Helicobacter pylori using nested polymerase chain reaction in gastric biopsy samples

Helicobacter pylori remains a controversial organism with regards to humans, its epidemiology still unclear nearly two decades after discovery. The present study was undertaken to estimate the prevalence of the organism in the gastrointestinal tract in symptomatic and asymptomatic subjects to understand its precise natural history in India. A total of 154 specimens were a part of the study. These included gastric biopsies from peptic ulcer disease and Non ulcer dyspepsia subjects, as visualized on endoscopy, saliva and stool samples from apparently normal healthy adults. Nested polymerase chain reaction was performed using the primers Hp1, Hp2, Hp3 targeting 16S rRNA gene. A prevalence of 65.1%, 100%, 66.7%, and 73.3% respectively was observed by polymerase chain reaction. No association was observed between the H.pylori status and the disease condition of the patient.     

Associations between user training and information systems success

What type and amount of computer-related training are available to information system (IS) users? And, how do these relate to their (users) perceptions of the success of the systems used? This paper reports on a study designed to answer such questions. Data were collected from 98 IS users in 16 different departments of 12 organizations. The results indicate that there exist positive associations between various types of computer-related training/educational programmes an organization provides to IS users and the perceived success of IS. Specifically, the availability of a computer resident expert in the organizational functional area of users has the most significant positive relationship with success.     

Gas between the stars

The interstellar gas in galaxies is heated by stellar radiation and cosmic rays and it also cools through radiation. We take a detailed look at these processes in order to understand the thermal state of equilibrium of the interstellar gas. This gas also manifests itself in different ‘phases’–molecular, neutral atomic and ionized, each with its characteristic temperature and density, which we attempt to understand.     

Private supplementary tutoring among primary students in Bangladesh

Using the databases created under Education Watch, a civil society initiative to monitor primary and basic education in Bangladesh, this paper explores trends, socioeconomic differentials and cost in private supplementary tutoring among primary students and its impact on learning achievement. The rate of primary school students getting access to private supplementary tutoring is increasing at two percentage points per year and reached 31% in 2005. Incidence of private tutoring was greater among boys and urban students than respective counterparts. Educated parents and well‐off families were more likely to arrange supplementary tutoring for their children. A wide variation in the cost for private tutoring prevailed. The tutees spent 46% of their total private expenditure for education on supplementary tutoring. Supplementary tutoring helped students learn more than those who had no such support. Private tutors for primary school students have become a well‐accepted norm. Finally, a number of social implications are discussed.