4 research outputs found
Hotbilder och framtidsutsikter för överlevnaden av den fenlösa Yangtze tumlaren
The Yangtze finless porpoise (Neophocaena phocaenoides asiaorientalis), is a small freshwater cetacean which has recently fallen dramatically in number. It is an endemic species for the Yangtze River and unless drastic action is taken, it risks the same fate as the now functionally extinct Yangtze river dolphin (Lipotes vexillifer). Threats to the porpoise are diverse but they have in common that they are caused by man. Development of the river has been made to supply a growing human population with food, hydropower, and to reduce the risk of flooding. These changes have resulted in a degraded habitat for the porpoise. A major problem is that the species natural behaviour and morphological adaptions to a life in a river exposes it to serious risks. Porpoises navigate by echolocalization and have poorly developed eyes due to the turbid water in the river. Today this navigation is made difficult by the heavy vessels trafficing the Yangtze River. It is common that porpoises collide with vessels which lead to injuries and even death. Another behaviour that causes problems is that the porpoise hunt near the river bottom. This is the area where fishermen lay down most of their fishing gear. This increases the risk that they will get entangled which ultimately leads to their death. Measures have been taken to try to save the species. Conservation work is conducted in captivity, ex situ and in situ. Ex situ work takes place largely in the restored oxbow lake Tianâe-Zhou where porpoises breed naturally in an environment with reduced fishing and vessel traffic. The in-situ work is performed in established reserves in the main river. In captivity, the porpoises reproduce successfully and behavioural research can be conducted on them. However, it is important to work towards a restoration of a decent living environment in the Yangtze River since in-situ conservation should be the goal of all conservation work. The Yangtze River is such an important resource for the local people, and the species living in and around it that a big effort should be applied to preserve it. It seems that the re-creation of oxbow lakes has favored the species and establishment of more of these semi-natural reserves would therefore be of further benefit. Even so, this alone will not suffice to ensure the porpoise future. In order to give the species a fair chance of survival, efforts from many directions is required. Industry, government, local people and not least consumers across the world must pull together to restore the Yangtze River, thus giving the Yangtze finless porpoise a chance to survive
Not all can become academics : a critical study of the governmentâs perspective on knowledge and grading policy
Bakgrund: Bakgrunden till vÄr uppsats grundar sig pÄ frÄgan vem skolan egentligen Àr till för. Vi tog sedan vÄr utgÄngspunkt i en förelÀsning av Sir Ken Robinson "Changing Education Paradigms". För att smalna av vÄrt forskningsomrÄde valde vi att inrikta oss mot betyg och dess konsekvenser. Syfte: Syftet med uppsatsen Àr att undersöka varför betyg existerar, vad vi betygsÀtter och hur det pÄverkar elever att bli betygsatta. Metod: Metoden som anvÀnts i uppsatsen Àr en diskursanalys, dÀr olika utdrag ur olika artiklar och publikationer (regering, skolminister, sjÀlvhjÀlpsbok) analyseras utifrÄn tvÄ teoretiker och tvÄ forskare. Resultat: I vÄr analys av vÄrt valda material framkommer en relativt oproblematisk syn pÄ kunskap och betyg, som innebÀr att fakta Àr fakta oavsett perspektiv. Analysen visar ocksÄ att uppfattningen om betyg inte stÀmmer överens med forskninge
Biomarker support for ADHD diagnosis based on Event Related Potentials and scores from an attention test
ADHD is a heterogeneous neurodevelopmental disorder associated with dysfunctions in several brain systems. Objective markers of brain dysfunction for clinical assessment are lacking. Many studies applying electroencephalography (EEG) and neuropsychological tests find significant differences between ADHD and controls, but the effect sizes (ES) are often too small for diagnostic purposes. This study aimed to compute a diagnostic index for ADHD by combining behavioral test scores from a cued visual go/no-go task and Event Related Potentials (ERPs). Sixty-one children (age 9â12 years) diagnosed with ADHD and 69 age- and gender-matched typically developing children (TDC) underwent EEG-recording while tested on a go/no-go task. Based on comparisons of ERP group-means and task-performance, variables that differed significantly between the groups with at least moderate ES were converted to a five points percentile scale and multiplied by the ES of the variable. The sum-scores of the variables constituted the diagnostic index. The index discriminated significantly between patients and TDC with a large ES. This index was applied to an independent sample (20 ADHD, 21 TDC), distinguishing the groups with an even larger ES. The diagnostic index described has the potential to support assessment. Further research establishing diagnostic indexes for differential diagnoses is needed