Context: Emergence is a term used to describe complex patterns or systems which are formed from very basic rules or agents. Once such example which has intrigued scientists across several fields has been ant colonies. Computer scientists are particularly interested in ant colonies as although each individual ant acts in a very simple manor, the ant colony as a whole is able to find shortest pat...

An antigen that clearly marked T helper cells was first identified when the W 3 / 2 5 mouse monoclonal ant ibody was raised against rat thymocytes (1, 2). T h e W 3 / 2 5 antigen appears to be equivalent to human T 4 antigen, which is now called CD4 (3), and to mouse L 3 T 4 antigen (4-6). Hencefor th , we will call the rat ant igen "CD4 (W3/25) ." Antibodies to CD4 antigens inhibit T helper ce...

Specialization in species interactions is of central importance for understanding the ecological structure and evolution of plant-animal mutualisms. Most plant-animal mutualisms are facultative and strongly asymmetric. In particular, myrmecochory (seed dispersal by ants) has been regarded as a very generalized interaction. Although some recent studies have suggested that only a few ant species ...

We demonstrated that mitochondrial phospholipid hydroperoxide glutathione peroxidase (PHGPx) first suppressed the dissociation of cytochrome c (cyt c) from cardiolipin (CL) in mitochondrial inner membranes and then apoptosis caused by the hypoglycaemia by the prevention of peroxidation of CL [Nomura, Imai, Koumura, Arai and Nakagawa (1999) J. Biol. Chem. 274, 29294-29302; Nomura, Imai, Koumura,...

Mound-building ants, and especially wood ants (Formica rufa group), are wide-spread key species that affect ecosystem functioning in several ways in the boreal forests of Eurasia. Forest clear-cutting harms wood ants, but the colonies gradually recover and multiply as forest succession proceeds. Thus their impact on ecosystem functioning may change with stand age. The objectives of this thesis ...

هدف: از چالش­های عمده بشریت افزایش افسردگی و اختلال عملکرد جنسی ناشی داروهای ضدافسردگی است. با توجه به نقش سلول­های سرتولی در اسپرماتوژنز، پژوهش حاضر، اثر داروی دولوکستین را بر زنده­مانی، آپوپتوزیس بیان ژن­های Bax و­ (Connexin 43) Cx43 بررسی کرده مواد روش‌‌ها: TM4 محیط DMEM/F12 حاوی %5/2 FBS، 5% سرم اسب %1 پنی سیلین-استرپتومایسین کشت شدند. دوزهای 30،60، 15، 5/7، 75/3 میکرو­گرم/ میلی­لیتر زمان­ه...

optimization of reservoir parameters is an important issue in petroleum exploration and production. the ant colony optimization(aco) is a recent approach to solve discrete and continuous optimization problems. in this paper, the ant colony optimization is usedas an intelligent tool to estimate reservoir rock properties. the methodology is illustrated by using a case study on shear wave velocity...

The maintenance scheduling of thermal generators is a large-scale combinatorial optimization problem with constraints. In this paper we introduce the Rank-Based Ant System algorithm based version of the Ant System. This algorithm reinforces local search in neighborhood of the best solution found in each iteration while implementing methods to slow convergence and facilitate exploration.Rank-Bas...

BACKGROUND This study examined substrate oxidation at high-intensity exercise and aimed to determine when fat oxidation ends (FATmin). We hypothesized the existence of a connection between the anaerobic threshold (AnT) and FATmin point. METHODS Breath-by-breath data obtained from indirect calorimetry during a graded treadmill test were used to measure substrate oxidation and maximal oxygen up...

Wild chimpanzees are known to have a different repertoire of tool use unique to each community. For example, "ant-dipping" is a tool use behavior known in several chimpanzee communities across Africa targeted at driver ants (Dorylus spp.) on the ground, whereas "ant-fishing," which is aimed at carpenter ants (Camponotus spp.) in trees, has primarily been observed among the chimpanzees of Mahale...