Current research in online pedagogy reveals that students persist and are more sucessful when faculty exhibit caring behaviors and demonstrate social presence (Gazza & Hunker, 2014). Faculty presence ...and caring behaviors pose a challenge in online educational settings due to lack of face to face interaction; faculty teaching accelerated online courses of 8 weeks or less may face additional obstacles due to the shortened time frame. This article presents findings of post licensure nursing students' perceptions of faculty presence and caring behaviors in accelerated online nursing courses. The study findings informed the establishment of recommendations with strategies for implementation to enhance online faculty social presence and caring behaviors for instructors who teach in accelerated online courses.
Changes in cortisol in plasma were used to assess stress when calves were restrained and then dehorned. Thirteen Holstein heifer calves between 3 and 4 wk of age were used over 4 d; each calf served ...as its own control. On d 1, 2, and 4, blood was sampled initially while calves were in a pen, 5 min after being placed in a restraint chute, and then at 5, 15, 30, and 45 min and 1, 2, 3, 4, 8, and 12 h after simulated or actual dehorning. On d 1, dehorning was simulated. On d 2 and 4, one horn bud of each calf was cauterized, respectively; sequence of horns (right, left) and dehorning instruments (conventional electrical, Buddex) were alternated for all calves. Day or previous dehorning procedures had no effect on initial concentrations of cortisol in plasma. However, after calves were placed in a chute, cortisol in plasma increased with each entrance. Cortisol in plasma peaked at 5 min posthandling (d 1, 11.3 ng/ml) or 15 min postdehorning (electrical, 21.9 ng/ml; Buddex, 20.7 ng/ml). These data suggest that both de-horning procedures resulted in similar rates of synthesis and secretion of cortisol
Coevolution may be defined as the process of reciprocal, adaptive genetic change in two or more species. Host-parasite interactions play an important role in the evolutionary ecology. The host ...phylogeny is independent, and the phylogeny of the parasite depends to some extent on the host. This review provides a description of several different methods for studying host-parasite relationships, along with a description of the underlying models and theoretical background for each. It also shows the possible applications of different methods and describes the advantages and drawbacks of different techniques.
Zusammenfassung
Hintergrund
Die Altersbestimmung von juvenilen Schmeißfliegen ist ein wichtiges Werkzeug zur Eingrenzung der minimalen Leichenliegezeit. Der vorliegende Beitrag präsentiert ...morphologische und histologische Landmarken der über 50% der juvenilen Entwicklung beanspruchenden Puppen für die beiden in Deutschland wichtigsten Arten
Calliphora vicina
und
Lucilia sericata
.
Methoden
Die Aufzucht erfolgte bei 25°C. Die Puppen wurden 24-stündlich entnommen und gewogen oder abgetötet; das Puparium der abgetöteten Individuen wurde entfernt und die Puppe fotografiert. Puppen wurden in Formalin fixiert und histologische Präparate (7 µm, HE-Färbung) zur Analyse der Zellkernvolumina und Adipozyten sowie der allgemeinen histologischen Merkmale angefertigt.
Ergebnisse
Zehn morphologische Landmarken wurden definiert und ein signifikanter Gewichtsverlust im Verlauf der Metamorphose beobachtet. Die Zellkerne zeigten eine Volumenreduktion von bis zu 25,3% während des ersten Tages der Histolyse; die Zahl der Fettzellen reduzierte sich um bis zu 52,4%.
Schlussfolgerungen
Morphologische Merkmale von Puppen der Arten
C. vicina
und
L. sericata
erlauben es, die Wachstumsrate bei einer Umgebungstemperatur von 25°C auf den Tag genau einzugrenzen. Histologische Parameter können die Ergebnisse bestätigen oder sogar verbessern.
Treatment of cyanuric chloride with chiral amines or esters of chiral amino acids gave chiral 2,4-dichloro-6-alkylamino-1,3,5-triazines (2-5) in 49-69% yield, which were found useful as coupling ...reagents. Enantioselective activation and enantioselective aminolysis in the presence of 2-5 was observed.
Molluscs are the most diverse group in respect of sexual systems and strategies. They can be dioecious with separate sexes or hermaphroditic. Within hermaphroditism, it is possible to distinguish a ...number of modifications of this type of reproduction, such as protandry, protogyny, sex reversal, or protandry with some overlap. It is thought that dioecy was ancestral because it occurs in most classes of molluscs. Hermaphroditism evolved independently several times, and sequential and simultaneous hermaphroditism are more closely related to each other than to dioecy. This publication presents a general review of sexual systems and strategies in terrestrial gastropods with special emphasis on mating, fertilization, presence of love darts, reproductive strategies (semelparity vs. iteroparity) and modes (oviparity, ovoviviparity, viviparity), production of eggs and egg cannibalism.
A combination of statistical mechanics and elements of genetic population theory has succeeded in reproducing features of ageing processes 1. At equilibrium one assumes a constant population pop as ...result of a balance between number of deaths and born individuals. However, if the inherited harmful mutations rate M is high, or intense hunting hunt takes place, all this may lead to extinction when pop(t) goes to zero after some time t. We focus on such critical features and simulate the time evolution within the bit-string Penna model 2. A computer word represents a genome and each bit corresponds to presence (1) or lack (0) of harmful mutation which is activated at age defined by the bit position. With each evolution step the age increases by one and next bit is disclosed bringing up a risk of another harmful mutation which may be terminal if the total number of these bad mutations reaches a threshold value T. Then the individual dies. It also may die for other reasons, hunting among them. If it survives, it gives birth to offsprings that compensates the losses in population. Each baby takes on the bit-string after parents. We used parameters as in 1 to recover results for the hunt identical with 0 and the mutation rate M identical with 1. Then we were scanning pop(hunt, M) after long time t in order to determine a critical line on the (hunt, M) plane such that population do not survive for larger hunt or M. In 3 we concluded that too many mutations lead to a phase transition for pop with suggestion of the critical exponent 1/2. In this work we observe second order phase transitions and hunting seems to make this transition smoother with a bigger exponent. Our findings do not support the results reported in 1 on overfishing when rather a rapid decrease in population indicates the opposite tendency, perhaps of the first order type of transition.
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