Abstract: We studied the relationship of reciprocity, gender, and racial composition (Caucasian, African American, cross-race) of adolescent friendship dyads to similarity and proximity in 136 young adolescents. We found that adolescents selected friends who were of the same gender and race and that female dyads were more similar than male dyads on verbal achievement and several personality dimensions. Caucasian dyads were more similar than African American dyads on verbal achievement, mental alertness, and dominance. African American adolescents had more contact with their best friends outside school, whereas Caucasian adolescent friends had more in-school contact. African American students had fewer reciprocal relationships than the Caucasian students. Cross-race friendships were less reciprocal than same-race friendships. Race and gender were important in determining friendship patterns. Similarity and proximity were more important than reciprocity in understanding early adolescent friendships.

Abstract: This paper gives a survey on biology and ecology of equine tapeworms as well as on pathogenesis, clinics, diagnosis, therapy, and prophylaxis of tapeworm infections.

Abstract: Ziel: Überprüfung der Tiergerechtheit von in der Bauweise unterschiedlichen
Futterabrufstationen für Pferde in Gruppenhaltung anhand ethologischer
und physiologischer Parameter. Material und Methoden: In 32
Offenlaufställen (452 Pferde) mit computergesteuerten Abrufstationen
für Kraftfutter und Heu erfolgten kontinuierliche Direktbeobachtungen
für je einen 24-Stunden-Tag (Tortenstückverfahren). Erfasst wurden: Aufenthaltsdauer,
Besuchshäufigkeit, Droh- und Meideverhalten im Fütterungsbereich,
Blockaden sowie Herzfrequenz und Integumentverletzungen.
Ergebnisse: Eine Durchlaufstation reduzierte die Zahl der Auseinandersetzungen
im Fütterungsbereich signifikant. Ansonsten erhöhten die
für das fressende Pferd tiergerechten Varianten (Fressstand mit Eingangssperre,
ohne Austreibehilfe) Besuchshäufigkeit und Aufenthaltsdauer und
steigerten somit auch die Anzahl an Drohgesten je Tier und Tag. Insgesamt
betrachtet kann jedoch die Anzahl an sozionegativen Interaktionen
im Fütterungsbereich der Abrufstationen als relativ gering eingestuft
werden. Die Herzfrequenz lag im Warteareal bei den meisten Pferden im
physiologischen Bereich (45,1 ± 12,42 Schläge/min), erhöhte sich jedoch
in der Abrufstation um ca. 20 Schläge/min. Einige Tiere zeigten möglicherweise
stressbedingt kurzfristig auffallend hohe Werte (≥ 100 Schläge/
min). Integumentverletzungen im Zusammenhang mit dem Fütterungssystem
traten nicht auf. Der wichtigste Einflussfaktor auf die Untersuchungskriterien
war der Betrieb (Fläche, Konzeption, Management).
Schlussfolgerung: Durchlaufstationen sind pferdegerechter als Rücklaufstationen.
Nicht tiergerecht sind Stationen mit stromführender Austreibehilfe.
Weitere bauliche Unterschiede der derzeitigen Futterabrufstationen
dürften eher von untergeordneter Bedeutung sein, vor allem da
Flächengebot und Konzeption der Offenstallanlage sowie das Management
die überprüften Kriterien zur Tiergerechtheit maßgeblich beeinflussen.
Untersuchungen zur Abklärung der Ursache für die vereinzelt aufgetretenen
sehr hohen Herzfrequenzwerte sollten durchgeführt werden.
Objective: Comparison with regard to animal welfare of different automatic
feeding systems for hay and concentrate in group housing systems
for horses using parameters of ethology and physiology. Material and
methods: Parameters of research comprised: duration of stay, frequency
of visit, threatening behaviour with and without risk of injury, and avoiding
behaviour as well as heart rate and injuries of the integument. 452
horses were observed at the feeding area of 32 run-out-sheds. Every group
of horses was continuously observed following the pie chart system for
24 hours. Results: The “walk-through” station significantly reduced the
number of conflicts in the feeding area, whereas those systems which are
appropriate for the feeding horses (feeding station with access barrier and
without stimulation device by electric shock) led to a higher frequency of
visits and a longer duration of stay resulting in more threatening gestures.
However, the number of negative interactions in the feeding area of the
feeding systems can all together be classified as relatively insignificant.
The heart rate was within the physiological range (45.1 ± 12.42 beats/min)
in the waiting area, but increased by approximately 20 beats/min on average
within the feeding station. Some horses showed a very high heart rate
(≥ 100 beats/min) while entering the feeding station, possibly stress-related.
There were no injuries of the integument associated with the feeding
systems. The most important factor of the observation criteria was the
individual group housing system with its different dimensions, conception
and management. Conclusion: “Walk-through” stations are better than
”walk-back” stations with regard to animal welfare. Likewise, automatic
feeding stations with a current-carrying stimulation device are not supportive
of good welfare. The other differences between the constructions
of feeding stations of present systems are probably of less importance, particularly
as it was shown that the stable (management, stable area, conception)
had a significant influence on the surveyed parameters. Investigations
to obtain information on the cause for the sporadic occurrence of
very high heart rate values should be undertaken.]

Abstract: Abstract This paper describes the domestic livestock of the Republic of Yemen and aspires to complement earlier sources listing or partially describing `breeds'. It attempts to cover all species and provide indications of production parameters through a literature review and via field observations made by the author in 1999. Information is provided on livestock numbers and the economic importance of animal production. Most animals are kept in sedentary mixed crop-livestock production systems; transhumant systems have the next greatest number of stock; with nomadic systems being of least and declining importance. Yemen's livestock appear to comprise at least 11 breeds of sheep, 5 breeds of goat, 2 breeds of cattle, 4 breeds of camel, 2 breeds of donkey and 1 breed of horse. There are no data on breeds of poultry but domestic fowl (where clearly considerable diversity exists) and pigeons are kept. There is little formal information on the history and relationships of most breeds. Some appear to be of ancient local origin, whereas others show affinities with those of neighbouring and other countries. None of the identified types is considered endangered, so conservation would be premature. A more formal and detailed genetic characterization, to add to the largely morphological and traditional classification, may, however, reveal such a need.

Abstract: The present study evaluated the engorgement and drop-off rhythms of Anocentor nitens females feeding on horses. Drop-off rhythm was evaluated at 6h-intervals (06:00, 12:00, 18:00, and 00:00 h) on horses held in stalls or in a pasture. A new method of marking feeding female ticks (the bowknot technique) was developed to evaluate ticks on horses in pasture that attached to different parts of the horse's body. This technique was highly successful, indicating no significant interference on tick engorgement rate or final tick weight, length and reproductive capability. Horses held in the pasture during the summer produced only 28.2% of the tick detachment during the daylight period from 06:00 to 18:00 h. In contrast, 53.4% of the ticks detached during this same 12 h-period during the winter. This difference was probably related to the longer scotoperiod during the winter. Different drop-off rhythms were observed for females attached to different anatomical parts of the horse's body. For example, ticks attached to the ears, perineum, and tail showed similar drop-off patterns, but were different from ticks attached to mane, rump and other body parts. The idiosoma length of the feeding female ticks was individually measured every 6 h until the engorged female detached naturally. The engorgement rate (increase in millimeters of the body length per hour) was evaluated during the last 96 h of parasitism. The highest engorgement rates were observed during the last 24 h of parasitism (approximately 0.16 mm/h), which were four-fold higher than the engorgement rates of the previous 3 days ( approximately 0.04 mm/h), demonstrating that these lower and higher values corresponded to the slow and rapid feeding phases reported elsewhere. Based on these data, the 6 mm idiosoma length was estimated as the minimal length that would correspond to the time point (i.e. 24 h before detachment) during which ticks would undergo the rapid feeding phase and detach as fully engorged females. When this 6 mm length was tested to estimate the number of engorged females detaching from horses in a period of 24 h, the estimated accuracy varied from 58.5 to 97.7% (mean: 73.3%).