Does Group Contact Shape Styles of Pictorial Representation? A Case Study of Australian Rock Art.

Image-making is a nearly universal human behavior, yet the visual strategies and conventions to represent things in pictures vary greatly over time and space. In particular, pictorial styles can differ in their degree of figurativeness, varying from intersubjectively recognizable representations of things to very stylized and abstract forms. Are there any patterns to this variability, and what might its ecological causes be? Experimental studies have shown that demography and the structure of interaction of cultural groups can play a key role: the greater the degree of contact with other groups, the more recognizable and less abstract are the representations. Here we test this hypothesis on a real-world dataset for the first time. We constructed a balanced database of Indigenous Australian rock art motifs from both isolated and contact Aboriginal groups (those often in contact with other groups). We then ran a survey asking participants to judge the recognizability of the motifs and to provide interpretations. Results show that motifs from contact Aboriginal groups were more likely to be judged as inter-subjectively recognizable and also elicited more convergent descriptions than motifs from isolated groups. This is consistent with the idea that intergroup contact is likely to be an important factor in the cultural evolution of pictorial representation. We discuss the implications of these findings for the archaeology and anthropology of art, and the parallels with language evolution.

Increase in histone methylation in the cat germinal vesicle related to acquisition of meiotic and developmental competence.

This study identified specific changes in histone lysine methylation patterns of the feline germinal vesicle (GV) during pre-antral-to-antral follicle transition, the latter being a key interval for competence acquisition. Oocytes from adult cats were isolated from pre-antral, early (≤ 0.5 mm diameter), small (0.6-1 mm) or large (1-3.5 mm) antral follicles and immuno-stained with anti-histones H3 trimethylated at lysine 9 (H3K9me3), lysine 4 (H3K4me3), lysine 27 (H3K27me3) or H3 dimethylated at lysine 79 (H3K79me2). The vast majority of oocytes (range, 72.2-85.4%; p > 0.05) contained a GV with H3K9me3 or H3K27me3, regardless of follicular stage/size. However, the proportion of GVs with H3K4me3 or H3K79me2 was higher in early antral follicles (42.6%; p < 0.05) compared with other stages (range, 12.1-15.2%). Therefore, H3K4me3 and H3K79me2 (both known to be associated with selective gene activation) appear to be reliable markers of onset of GV competence during the pre-antral-to-antral transition phase. By contrast, H3K9me3 and H3K27me3 (both known to be related to selective gene repression) seem more linked to expression patterns during the GV stage and are less useful indicators during the entire folliculogenesis interval.

Efficacy of four density gradient separation media to remove erythrocytes and nonviable sperm from canine semen.

The objective was to compare four commercially available density gradient centrifugation (DGC) media (ISolate [Irvine Scientific; Santa Ana, CA, USA], Percoll [Pharmacia; Uppsala, Sweden], PureCeption [SAGE In-Vitro Fertilization, Inc.; Trumbull, CT, USA], PureSperm 100 [Nidacon International AB; Molndal, Sweden]) for their ability to separate viable, motile sperm from contaminant nonviable (immotile and/or dead) sperm and red blood cells (RBC). Pooled sperm-rich fractions from four healthy dogs were assessed using Spermvison SAR (Minitube of America). For this, 1 mL of the blood/sperm admixture was pipetted over 4 mL of DGC media: 50%/90% ISolate (Irvine Scientific), 45%/90% Percoll (Pharmacia), 40%/80% PureCeption (SAGE In-Vitro Fertilization, Inc.), and 40%/80% PureSperm 100 (Nidacon International AB). After centrifugation, five 1-mL fractions (A, B, C, D, and E) and the sperm pellet (bottom fraction F) were separated. Sperm morphology and red blood cell/sperm ratio (RBC/S) per fraction were determined on stained slides. All DGC media separated RBC from sperm; the highest red blood cell/sperm ratio was present in ISolate (Irvine Scientific) and Percoll (Pharmacia) fraction A (29.4±29.7 and 28.2±20.8, respectively), and in fractions A and B of both PureCeption (SAGE In-Vitro Fertilization, Inc.) (37.0±22.8 and 39.6±24.3, respectively) and PureSperm 100 (Nidacon International AB) (25.2±5.9 and 23.0±3.9, respectively). The fractions with the highest total sperm recovery, motile sperm recovery, as well as overall motility were ISolate (Irvine Scientific) and Percoll (Pharmacia) fraction D (33.9±29.4%; 40.99±27.9%; 71.2±21.8% and 36.4±14.5%; 39.3±15.8%; 88.6±2.3%, respectively), and for PureCeption (SAGE In-Vitro Fertilization, Inc.) and PureSperm 100 (Nidacon International AB), the sperm pellet, fraction F (78.8±28.3%; 88.0±17.4%; 70.2±11.1% and 73.1±21.0%; 75.4±24.6%; 80.6±17.1%, respectively). In the pellet for PureCeption (SAGE In-Vitro Fertilization, Inc.), more sperm and motile sperm were recovered than in ISolate (Irvine Scientific) and Percoll (Pharmacia) fractions D (P<0.0163). Therefore, DGC media should be considered for canine semen purification when contaminated with blood or when separation of motile versus immotile sperm is needed.

Defining biological communication.

Communication is ubiquitous in biology, and agreement on terms essential for scientific progress. Yet there is no agreed definition of biological communication. Definitions couched in terms of adaptation are often used, but there is significant variability in exactly which criteria are invoked. An alternative is to define communication in terms of information transfer. This article reviews the merits of these approaches, and argues that the former is to be preferred, so long as we demand that both the signal and the response be adaptive, rather than just one or the other, as is common. Specific concerns with the definition are addressed, and it is then explained why an account of communication predicated on information transfer is necessarily derivative upon such an approach. Other alternatives and some variants of the adaptationist definition are also briefly discussed.

Concentric and eccentric shoulder rehabilitation biomechanics.

The use of an impulse-momentum (IM) exercise technique was investigated for end-stage shoulder rehabilitation. The objectives of this study were to: (a) quantify the net shoulder joint forces and moments while using an IM system and (b) test the influence of gender and muscle loading type (concentric or eccentric) on kinetic and kinematic parameters. Fourteen healthy adults (eight males, six females) performed a repeated measures experiment on an instrumented device utilizing a cabled shuttle system. While maintaining 90 degrees of shoulder abduction and 90 degrees of elbow flexion, the subjects externally rotated their upper arm from 0 degrees to 90 degrees (concentric acceleration) and then internally rotated their upper arm back from 90 degrees to the 0 degrees position (eccentric deceleration). Shoulder joint forces and moments as well as rotational work and power were calculated using inverse dynamics (free-body forces and moments calculated at intersegmental joint centres). Overall concentric peak forces and moments were greater than eccentric peak forces and moments (P < 0.0001). Joint forces and moments reached a maximum during the initial phase of concentric loading (0 degrees to 45 degrees) compared with any other rotational position in the loading cycle (concentric 45 degrees to 90 degrees or eccentric 90 degrees to 0 degrees). The results also indicate that males experienced higher (P < 0.0001) average resultant peak joint forces (concentric 0 degrees to 45 degrees = 108.0 N and eccentric 90 degrees to 45 degrees = 87.2 N) than females (concentric 0 degrees to 45 degrees = 74.7 N and eccentric 45 degrees to 0 degrees = 56.0 N). In addition, males experienced higher (P < 0.0001) average resultant peak joint moments (concentric 0 degrees to 45 degrees = 30.4 N m and eccentric 45 degrees to 0 degrees = 21.0 N m) than females (concentric 0 degrees to 45 degrees = 19.7 N m and eccentric 45 degrees to 0 degrees = 12.8 N m).

Selective control of the estrous cycle of the dog through suppression of estrus and reduction of the length of anestrus.

The objective of this study was to determine the effectiveness of testosterone in suppressing estrus in the bitch, and of cabergoline in shortening the length of the subsequent anestrous period. In Experiment 1, 12 diestrual Beagle bitches were randomly divided into two groups when plasma progesterone (P(4)) concentration was <1 ng/ml (Day 0). Starting on Day 0, bitches in Group 1 (n=6) were treated with testosterone cypionate every 14 days for a total of 239 days, and bitches in Group 2 served as untreated controls. On Day 274, bitches in both groups were treated with cabergoline for 40 days and blood samples were obtained on Days 274, 276 and 279 for determination of plasma prolactin (PRL) concentrations using RIA. All bitches were observed for proestrual bleeding during treatment with cabergoline. In Experiment 2, 12 Greyhound bitches previously treated with testosterone within the last 6 months were randomly divided into two groups. At the initiation of this experiment, P(4) concentration was determined to verify that all bitches had a concentration of <1 ng/ml (Day 0). Starting on Day 0, bitches in Group 1 (n=6) were treated with cabergoline for 36 days, and bitches in Group 2 (n=6) served as untreated controls. Blood samples were obtained on Days 0, 2 and 5 to determine PRL concentrations. All bitches were observed for proestrual bleeding during treatment with cabergoline. In Experiment 1, one bitch (Group 1) exhibited estrus after treatment with testosterone (1mg/kg body weight) for 43 days, and one bitch (Group 1) exhibited estrus after treatment with testosterone (2mg/kg body weight) for 113 days. None of the other four bitches in Group 1 exhibited estrus during the period of testosterone treatment (239 days). All bitches in Group 2 (control) exhibited estrus during the 239 days of the study. In addition, five of the six testosterone-treated bitches showed signs of proestrual bleeding within an average of 12.6 days (range of 5-25 days) after treatment with cabergoline; and, four of the six nontestosterone bitches showed signs of proestrual bleeding within an average of 28 days (range of 6-46 days). Prolactin concentrations in bitches in both Groups 1 and 2 significantly decreased after treatment with cabergoline. In Experiment 2, one of the six bitches showed signs of proestrual bleeding within 15 days after treatment with cabergoline. From the results of this study, it was concluded that exogenous testosterone was moderately effective (66%) in suppressing estrus in Beagle bitches, and cabergoline was effective in shortening the length of the anestrous period of Beagle bitches whose estrous cycle was previously suppressed with exogenous testosterone, but less effective in shortening the length of the anestrous period in Greyhound bitches previously treated with testosterone to suppress estrus.

Persistent fatigue in well women.

Fatigue is the subjective report of a sustained sense of exhaustion with reduced motivation and capacity for physical and/or mental activity. Although factors associated with fatigue have been explored in specific patient populations, minimal study has been devoted to exploring both the magnitude of fatigue and associated variables among women generally thought to be well. This cross-sectional, descriptive study examined the relationship of behavioral, socio-demographic, and emotional factors to subjective ratings of fatigue among women in the community who perceived themselves as being fatigued but otherwise healthy. A convenience sample of 155 adult women completed the Piper Fatigue Self-Report Scale (PFS), the Beck Depression Inventory (BDI), and an investigator-designed questionnaire that collected behavioral and socio-demographic data. Correlation and regression analyses were used with fatigue as measured by the PFS as the outcome variable. Statistically significant relationships were noted between PFS and BDI scores as well as PFS and sleep pattern, rest quality, and perceived stress. Construction of a multiple regression model revealed an adjusted R2 of .43 with the BDI score serving as the major predictor variable for fatigue. Persistent fatigue is a consistent element in the lives of many women. As such it can significantly undermine women's quality of life.