Thick and thin fingers point out Turing waves

Mouse genetics and computer simulations demonstrate that digit number and width are controlled by a Turing-type mechanism in which distal Hox genes modulate periodicity.     

Partner preferences in the context of concurrency: What Himba want in formal and informal partners

Research on human mate preferences that distinguishes between short- and long-term partners has been conducted mainly in industrialized societies, where multiple mating and concurrent partnerships are stigmatized. However, cross-culturally, there is significant variation in the frequency and the level of acceptance of such relationships. Furthermore, the dichotomy between short- and long-term partnerships does not fully describe the diversity in actual extra-pair behavior, which ranges from single sexual encounters to multi-year love affairs. Here we present another comparison, between formal (marital) and informal (non-marital) partners, which we feel better captures this diversity. We assess the traits that men and women prefer in each type of partner among Himba pastoralists, where concurrent partnerships are common and accepted for both sexes. We situate our findings in relation to three main explanations for concurrent partnerships: dual-mating, trading-up and multiple investors. We find some similarities with the existing literature in the traits that are listed as important, including physical attractiveness, wealth and intelligence. Our evidence suggest that Himba men follow a dual strategy, preferring hard-working wives and attractive girlfriends. Women's preferences align most strongly with a multiple investors explanation, most clearly articulated through their preferences for wealthy husbands and generous boyfriends. Limited support is also found for a dual-mating strategy in women. These findings suggest that local cultural norms and ecologies modulate mate preferences in important ways.     

Abnormal Epidermal Keratinization in the repeated epilation mutant mouse

Repeated epilation (Er) is a radiation-induced, autosomal, incomplete dominant mutation in mice which is expressed in heterozygotes but is lethal in the homozygous condition. Many effects of the mutation occur in skin: the epidermis in Er/Er mice is adhesive (oral and nasal orifices fuse, limbs adhere to the body wall), hyperplastic, and fails to undergo terminal differentiation. Skin from fetal +/+, Er/+ and Er/Er mice at ages pre- and postkeratinization examined by light, scanning, and transmission electron microscopy showed marked abnormalities in tissue architecture, differentiation, and cell structure; light and dark basal epidermal cells were separated by wide intercellular spaces, joined by few desmosomes, and contained phagolysomes. The numbers of spinous, granular, and superficial layers were highly variable within any given region and among various regions of the body. In some areas, 2-8 layers of granular cells, containing large or diminutive keratohyalin granules, extended to the epidermal surface; in others, the granular layers were covered by several layers of partially keratinized or nonkeratinized cells. In rare instances, a single or small group of cornified cells was present among the granular layers but was not associated with the epidermal surface. Both the granular and nonkeratinized/partially keratinized upper epidermal layers Er/Er skin gave positive immunofluorescence with antiserum to the histidine-rich, basic protein, filaggrin. Proteins in epidermal extracts from +/+, Er/+ and Er/Er mice were separated and identified by radio- and immunolabeling techniques. The Er/Er extract was missing a 26.5- kdalton protein and had an altered ratio of bands in the keratin region. The 26.5-kdalton band was histidine-rich and cross-reacted with the antiserum to rat filaggrin. Several high molecular weight bands present in both Er/Er and +/+ extracts also reacted with the antiserum. These are presumed to be the precursors of filaggrin and to account for the immunofluorescence om Er/Er epidermis even though the product protein is absent. The morphologic and biochemical data indicated that the genetic defect has a general and profound influence on epidermal differentiation, including alteration of two proteins (filaggrin and keratin) important in normal terminal differentiation, tissue architecture, and cytology. Identification of epidermal abnormalities at early stages of development (prekeratinization) and defective structure of other tissues and gross anatomy suggest that the mutation is responsible for a defect in same regulatory step important in many processes of differentiation and development.     

ENVIRONMENTAL CONDITIONS, GROWTH AND PRODUCTION OF ANADARA SENILIS (LINNAEUS, 1758) IN A SENEGAL LAGOON

Two populations of Anadara senilis were sampled periodicallyin a lagoon of Senegal. Spatfall occurs in summer during therainy season. Population density decreases from about 50, 000.m^–2,two months after spatfall, down to 6, 750 one year later and750 after 28 months. The average growth, measured on the surfaceof the shell, following the umbo rim axis is 0.8 mm per month.The main reduction in growth rate occurs in winter and endsby the deposition of a growth ring. A second growth reductiontakes place during the rainy season and sometimes ends by aweak growth ring. The microgrowth increments are conspicuousand widest during spring equinox. They are not directly relatedto the tidal cycle, but it was impossible to determine if theyhave a tidal or a daily periodicity. (Received 11 February 1990; accepted 16 July 1993)     

MUCIDS: an operative C environment for acquisition and processing of polarized-light scattered from biological specimens

In this work, we describe a software package, MUCIDS, completelydeveloped in our laboratory, for acquisition and processingof differential polarizxition light-scattering data from specimensof biophysical interest. MUCIDS is a C environment that managesthe whole activity of an instrument used for measurements ofMueller matrix scattering elements. It allows one to capture,analyse, process and display data from this or from other similarlight-scattering experiments. The entire system is suitablefor routine measurements in a general biophysical (or microbiological)laboratory because of its easy handling and maintenance. Thesoftware was written in C lattice and will run on IBM personalcomputers and similar. It uses IBM/DAC and GPIB/IBM interfacecards. Received on October 3, 1989; accepted on March 26, 1990     

Seasonal variation in various blood indices of the kangaroo rat, Dipodomys panamintinus

1. Various blood indices in the Panamint kangaroo rat revealed seasonal fluctuations. The red blood cell count during winter and summer averaged 7.2 +/- 1.0 X 10(6) and 9.2 +/- 0.2 X 10(6)/mm3 respectively. 2. The mean cell hemoglobin during winter and summer averaged 25 +/- 10.8 pg and 18.6 +/- 3.7 pg respectively. 3. These fluctuations may reveal a rapid rate of red blood cell destruction during winter in combination with a change in diet, concomitant to this, is an increase in mean cell hemoglobin of the surviving red blood cells.