THE IMPACTS OF DIFFERENT TYPES OF COLLEGE INSTRUCTORS ON STUDENTS’ ACADEMIC AND LABOR MARKET OUTCOMES

Based on a novel data set that links college administrative information with earnings records from a state college system for both public two‐year and four‐year colleges, this study quantifies the impacts of exposure to different types of instructors during students’ initial semester in college on their subsequent academic and labor market outcomes. To minimize bias from student sorting by type of instructor, we combine course‐set fixed effects with an instrumental variables approach that exploits term‐by‐term fluctuations in faculty composition in each department, therefore controlling for both between‐ and within‐course sorting. The findings suggest that two‐year students, particularly racial minority students, have substantially higher levels of exposure to adjuncts with temporary appointments than four‐year students. Two‐year students taking a heavy course schedule with temporary adjuncts are adversely affected in college persistence and subsequent credit accumulation, and the penalty is particularly pronounced among males and racial minority students with stronger academic potential. Such negative impacts on academic outcomes do not translate into poorer short‐ to medium‐term labor market performance. In the four‐year setting, no significant distinction is identified between different types of instructors on either student academic or labor market outcomes.     

Identification of Different Forms of Cocaine and Substances Used in Adulteration Using Near‐infrared Raman Spectroscopy and Infrared Absorption Spectroscopy

Identification of cocaine and subsequent quantification immediately after seizure are problems for the police in developing countries such as Brazil. This work proposes a comparison between the Raman and FT‐IR techniques as methods to identify cocaine, the adulterants used to increase volume, and possible degradation products in samples seized by the police. Near‐infrared Raman spectra (785 nm excitation, 10 sec exposure time) and FT‐IR‐ATR spectra were obtained from different samples of street cocaine and some substances commonly used as adulterants. Freebase powder, hydrochloride powder, and crack rock can be distinguished by both Raman and FT‐IR spectroscopies, revealing differences in their chemical structure. Most of the samples showed characteristic peaks of degradation products such as benzoylecgonine and benzoic acid, and some presented evidence of adulteration with aluminum sulfate and sodium carbonate. Raman spectroscopy is better than FT‐IR for identifying benzoic acid and inorganic adulterants in cocaine.     

Forensic Use of A Subtropical Blowfly: The First Case Indicating Minimum Postmortem Interval (mPMI) in Southern Brazil and First Record of Sarconesia Chlorogaster from a Human Corpse

Southern Brazil is unique due to its subtropical climate. Here, we report on the first forensic entomology case and the first record of Sarconesia chlorogaster (Wiedemann) in a human corpse in this region. Flies' samples were collected from a body indoors at 20°C. Four species were found, but only Chrysomya albiceps (Wiedemann) and S. chlorogaster were used to estimate the minimum postmortem interval (mPMI). The mPMI was calculated using accumulated degree hour (ADH) and developmental time. The S. chlorogaster puparium collected was light in color, so we used an experiment to establish a more accurate estimate for time since initiation of pupation where we found full tanning after 3 h. Development of C. albiceps at 20°C to the end of the third instar is 7.4 days. The mPMI based on S. chlorogaster (developmental time until the third instar with no more than 3 h of pupae development) was 7.6 days.     

东北地区城镇体系发展的产业支撑体系培育

东北地区城镇体系与产业发展呈现出较强的适应与反馈的互动关联态势,伴随着产业结构的高级化,必将促进东北地区城镇空间结构载体功能强化以及城镇体系发展的外向化,并认为产业空间协调与城市群整合、产业体系重构与地域优化及产业升级与城市职能体系优化等是产业支撑东北地区城镇体系发展的重点。     

基本权利的国家保护义务——以德、中两国为审视对象

近代立宪主义以保证"国家不得为非"为目的,现代立宪主义在福利国家等思潮背景下使得现代国家职能大幅扩张,发展出基本权利的国家保护义务。基本权利的防御权功能和客观秩序功能是德国基本权利普遍具有的两项功能,防御权功能为核心功能。现代国家职能基本化约为立法、行政与司法三种职能,国家保护义务相应地表现为立法者制定完善法律的义务;行政权切实执行法律的义务和司法机关提供完善的司法救济义务。国家保护义务存在一定的界限,我国现行宪法在基本权利的规定与现实保障方面存在诸多不足,需加以改善。     

谈公安院校素质教育

公安院校大学生要具备过硬的政治素质和相当的军事素养,在身体素质方面更要具有与公安工作相适应的身体对抗性、快速反应性和连续作战的抗疲劳能力。基于公安工作对公安院校大学生在素质方面提出的更高要求,公安院校要加快推进素质教育。     

我国大学生自杀原因综述

本文综述了近几年我国大学生自杀现象的原因,并将其归类为大学生的生理因素、心理因素、生活态度、外在因素、家庭因素和社会因素六个主要的维度进行阐述.     

日粮锌硒水平对肉鸡小肠黏膜结构的影响

为了探讨微量元素锌和硒互作对肉鸡小肠黏膜结构的影响 ,将 2 4只 1日龄AA肉鸡随机分为 3组 ,分别饲喂添加有高锌高硒 (锌 1 0 0 0mg/kg ,硒 5mg/kg)、低锌低硒 (锌 34mg/kg ,硒 0 .0 8mg/kg)和常锌常硒 (锌 5 0mg/kg ,硒 0 .1 5mg/kg)的日粮 4 5d后 ,观察小肠黏膜的形态结构变化。结果表明 ,高锌高硒或低锌低硒组肉鸡的小肠黏膜结构有明显的损伤 ,表现为黏膜厚度和绒毛高度下降 ,绒毛高度 /腺窝深度的比值减少 ,肠黏膜上皮细胞萎缩。尤其是高锌高硒对空肠的损伤最为严重。而常锌常硒组肉鸡小肠黏膜的形态结构正常。研究结果表明 ,日粮中按锌 5 0mg/kg和硒 0 .1 5mg/kg的比例添加 ,对于维持小肠黏膜的正常形态结构是合适的 ;过高或过低的锌和硒对小肠黏膜有毒性作用 ,且高锌和高硒可相互促进其毒性作用