期刊评价：影响因子及其相关指标

在西部大开发环境下，联系陕西省科技期刊的现状，研究了陕西省科技期刊的发展策略，首次提出“寓发展于服务中、中陕西省科技期刊与西部大开发的结合点。指出陕西省科技期刊发展的基本原则是坚持两个效益辩证统一，发展的出发点是服务西部大开发。     

The effects of substrate and fluid provision on thermoregulatory and metabolic responses to prolonged exercise in a hot environment

A high ambient temperature reduces the capacity to perform prolonged exercise. Total carbohydrate oxidation is less, and thus glycogen depletion is not limiting. Fluid ingestion in the heat should, therefore, focus on maintenance of hydration status rather than on substrate provision. Six healthy males cycled to exhaustion at 60% of maximum oxygen consumption (VO 2max ) with no drink, ingestion of a 15% carbohydrate-electrolyte drink (1.45 - 0.29 litres) or ingestion of a 2% carbohydrate-electrolyte drink (3.12 - 0.47 litres). The ambient temperature was 30.2 - 0.6°C (mean - s ), with a relative humidity of 71 - 1% and an air speed of approximately 0.7 m.s -1 on all trials. Weighted mean skin temperature, rectal temperature and heart rate were recorded and venous samples drawn for determination of plasma volume changes, blood metabolites, serum electrolytes and osmolality. Expired gas was collected to estimate rates of fuel oxidation. Exercise capacity was significantly ( P ? 0.05) different in all trials. The median (range) time to exhaustion was 70.9 min (39.4-97.4 min) in the no-drink trial, 84.0 min (62.7-145 min) in the 15% carbohydrate trial and 118 min (82.6-168 min) in the 2% carbohydrate trial. The 15% carbohydrate drink resulted in significantly ( P ? 0.05) elevated blood glucose and total carbohydrate oxidation compared with the no-drink trial. The 2% carbohydrate drink restored plasma volume to pre-exercise values by the end of exercise. No differences were observed in other thermoregulatory or cardiorespiratory responses between trials. These results suggest that fluid replacement with a large volume of a dilute carbohydrate drink is beneficial during exercise in the heat, but the precise mechanisms for the improved exercise capacity are unclear.     

Contextual factors that sustain innovative pedagogical practice using technology: an international study

Pedagogical innovation—whether involving technology or not—is shaped by a complex interaction of the innovation with contextual factors such as school and school district policy, leadership, cultural norms and values, teacher attitudes and skills, and student characteristics. This study examined school and classroom contexts in which pedagogical innovations employing technology were successfully sustained. Data were obtained from 59 cases drawn from the Second Information Technology in Education Study—Module 2, a project that examined 174 cases of innovative pedagogical practice in schools in 28 countries. An explanatory model of sustainability was derived from a qualitative analysis of the cases using grounded theory techniques. Essential conditions for the sustainability of classroom innovation were teacher and student support of the innovation, teacher perceived value of the innovation, teacher professional development, and principal approval. Contributing factors for sustainability were supportive plans and policies, funding, innovation champions, and internal and external recognition and support. An interactive website that allows for searching of SITES-M2 case reports on various attributes such as sustainability, transferability, level of school, and evidence of supportive policies and plans is available at http://sitesm2.org.     

Explaining organizational knowledge creation with a knowledge maturing model

Social media challenge knowledge management because of encouraging conversations, networking and participation in more distributed, diverse and dynamic ways of knowledge development and increasingly important individuals’ interests driving them. Hence, we need to understand the complex relationships between different qualities of knowledge developed in informal and formal processes as well as for overcoming misalignments in routines, tools and infrastructures supporting organizational knowledge creation. This paper contributes a maturation perspective towards explaining organizational knowledge creation and presents a knowledge maturing model, which is grounded in organizational practice and validated with qualitative and quantitative empirical and design studies. The results describe how characteristics of knowledge and support by IT change between phases of knowledge maturing. Our findings confirm theories of organizational knowledge creation with respect to expanding scopes from individuals through communities to organizations moving from interest-driven knowledge exploration in informal contexts to goal-driven knowledge exploitation in formal contexts. The maturation perspective adds to our understanding that organizational knowledge creation is not simply a continuous process. Phases that emphasize changeability alternate with phases concerned with stability. Knowledge develops in contexts that need to switch multiple times between opening up for new knowledge and filtering relevant knowledge and between de- and re-contextualization.     

Shifting the Perspective of the Research Librarian: A CoResearch Paradigm

This article proposes the coresearch engagement model (CoRE), which addresses how the academic research librarian can become a coresearch partner with any patron. The CoRE model is an interpersonal process and is founded upon the concepts of mutual respect, collaboration, reciprocity, and empowerment. Grounded in Howard Gardner’s multiple intelligences theory, Malcolm Knowles’ andragogical model, and guidelines from the Reference and User Services Association, CoRE has the potential to result in engagement for the librarian and patron. The CoRE model can be utilized in many ways including self-awareness and development for those who need and want to expand their abilities as a research librarian. It provides a theoretical framework and a knowledge base, in addition to giving a context for further development by expanding, comparing the related theories for further research, and implementing various applications suggested by this article.     

Early manifestations of intellectual performance: Evidence that genetic effects on later academic test performance are mediated through verbal performance in early childhood

Intellectual performance is highly heritable and robustly predicts lifelong health and success but the earliest manifestations of genetic effects on this asset are not well understood. This study examined whether early executive function (EF) or verbal performance mediate genetic influences on subsequent intellectual performance, in 561 U.S.-based adoptees (57% male) and their birth and adoptive parents (70% and 92% White, 13% and 4% African American, 7% and 2% Latinx, respectively), administered measures in 2003–2017. Genetic influences on children's academic performance at 7 years were mediated by verbal performance at 4.5 years (β = .22, 95% CI [0.08, 0.35], p = .002) and not via EF, indicating that verbal performance is an early manifestation of genetic propensity for intellectual performance.     

Relating deaf students' reading and language scores at college entry to their degree completion rates

Graduation patterns were examined for 905 deaf students (1990-1998) at the National Technical Institute for the Deaf. Students with higher reading and language skills had the best overall graduation percentage. Comparison of recipients of different degrees--bachelor of science (BS) versus fine arts (BFA); associate of applied science (AAS) versus occupational studies (AOS)--showed 92% of BS and 82% of AAS graduates reading at the 9th-grade level or above, versus 65% of BFA and 47% of AOS graduates. Interestingly, 80% of non-degree-earning students read at the 9th-12th grade levels; in absolute terms, they outnumbered graduates with similar reading skills in the AAS and BFA programs combined, and in the BS program. This indicates a need for improved counseling, placement, and retention strategies. Students performed similarly across degree categories, regardless of curriculum requirements and difficulty. Only non-degree-earning students had significantly lower grade averages.     

DIELECTRIC STUDIES OF UREASE AS A FUNCTION OF HYDRATION

The steady-state electrical conductivity,as well as the dielectric propertiesbetween 2×10~(-4)Hz and 100 kHz,and at 1 GHz,are reported for urease compressed powdersamples of low hydration.The results show that the large,low frequency dielectricdispersion,known as α-dispersion,is due to the build-up of a space charge of protons atthe sample-electrode interfaces.A smaller dispersion,appearing at higher frequencies,isconcluded to be associated with hindered motions of the peptide residues in the molecularstructure of urease.The extent of these polypeptide backbone motions is shown to bestrongly depended on the extent of enzyme hydration.This work is contributed to the de-velopment of conductimetric biosensors.     

Errors in the estimation of hydration status from changes in body mass

Abstract

Hydration status is not easily measured, but acute changes in hydration status are often estimated from body mass change. Changes in body mass are also often used as a proxy measure for sweat losses. There are, however, several sources of error that may give rise to misleading results, and our aim in this paper is to quantify these potential errors. Respiratory water losses can be substantial during hard work in dry environments. Mass loss also results from substrate oxidation, but this generates water of oxidation which is added to the body water pool, thus dissociating changes in body mass and hydration status: fat oxidation actually results in a net gain in body mass as the mass of carbon dioxide generated is less than the mass of oxygen consumed. Water stored with muscle glycogen is presumed to be made available as endogenous carbohydrate stores are oxidized. Fluid ingestion and sweat loss complicate the picture by altering body water distribution. Loss of hypotonic sweat results in increased osmolality of body fluids. Urine and faecal losses can be measured easily, but changes in the water content of the bladder and the gastrointestinal tract cannot. Body mass change is not always a reliable measure of changes in hydration status and substantial loss of mass may occur without an effective net negative fluid balance.