Burrowing,feeding, egestion and energy budgets of Allolobophora rosea (Savigny) (Lumbricidae)

Summary Allolobophora rosea (Savigny) was found to be common in mull type soils beneath bramble (Rubus fruticosus L.). Burrow construction in this soil type in the laboratory at 4.4, 10.0 and 14.8°C ranged between 133 and 516 mm g^-1 fresh wt of worm day^-1. Burrowing was affected by both body size and temperature. Rates of soil displacement during burrowing were estimated from burrowing rates, burrow dimensions and soil density; depending on body size and temperature they were in the range 809–1,928 mg dry wt of soil g^-1 fresh wt of worm day^-1. These values were in reasonable agreement with measured egestion rates (range: 1,000–2,000 mg dry wt of egesta g^-1 fresh wt of worm day^-1). It was concluded that A. rosea eats its way through the soil and is adapted to its rapid turnover. Gut turnover times were calculated to be between 1 and 2.5 h.Direct observation indicated that feeding was by a grazing procedure and it was shown that A. rosea preferentially selects the more organic fractions of the soil for ingestion.The evaluation of energy budgets for individual small immature, large immature and adult worms at 10°C revealed respiration to production ratios (R/P) of 1.0, 1.8 and 4.1, respectively. Assimilation efficiencies (A/C) were always less than 2.5%.     

Electron spin resonance spectrum of species “X” which may function as the primary electron acceptor in Photosystem I of green plant photosynthesis

Purified Photosystem I particles from spinach when reduced with 10 mM dithionite at pH 9 exhibited a 50% light reversible-ESR Signal 1 (P-700⁺) at about 10 K. It was possible to show by signal-averaging techniques that a light-reversible ESR spectrum concomitant with the reversible Signal 1 can be observed with approximate principal g factors at g = 2.07, g = 1.86 and g = 1.75.     

Immune competence in breast cancer — Relationship of pretreatment immunologic tests to diagnosis and tumor stage

Summary The immune competence of a group of 276 patients with suspected breast cancer has been assessed using a spectrum of tests: the peripheral lymphocyte count, serum immunoglobulin levels, lymphocyte response to phytohemagglutinin (PHA), Mantoux test, and dinitrochlorobenzene (DNCB) skin test. All tests were completed prior to any form of treatment as the initial part of an ongoing, long-term assessment which will ultimately relate immune competence to prognosis. 225 patients with breast cancer were allocated into stages based on their TNM status. The remaining 51 patients proved to have benign breast disease and made up the control group. In analysis, control patients were compared with early breast cancer patients, while the effect of advancing disease was assessed by betweenstage comparisons in the cancer group.There were no significant differences between early breast cancer and control patients or between cancer stages in peripheral lymphocyte count, serum immunoglobulin levels, lymphocyte response to PHA, or Mantoux responses. Age was found to have a crucial effect on some of these parameters and some apparent differences between the various groups lost significance after appropriate allowances were made for age.Important differences seen with the DNCB test persisted after allowing for age effects. Responses to DNCB were significantly depressed in patients with early breast cancer compared to controls. Patients with disseminated cancer showed greater depression than early breast cancer patients, but surprisingly, patients with locally advanced tumors had good responses to DNCB. Possible reasons for the paradoxical preservation of DNCB reactivity in patients with locally advanced cancer are discussed.The DNCB test is the most discriminating of the five tests of immune function studied.     

Operation Crayweed: Ecological and sociocultural aspects of restoring Sydney’s underwater forests

Operation Crayweed focuses on the restoration of underwater forests that disappeared from the coastline of Sydney, Australia’s largest city, 40 years previously. We show how a combination of science, hands‐on restoration, community engagement and art has helped the project to reach its goals as well as raise awareness about the importance of underwater kelp forests that are experiencing global decline.     

Automatically Generated Algorithms for the Vertex Coloring Problem

The vertex coloring problem is a classical problem in combinatorial optimization that consists of assigning a color to each vertex of a graph such that no adjacent vertices share the same color, minimizing the number of colors used. Despite the various practical applications that exist for this problem, its NP-hardness still represents a computational challenge. Some of the best computational results obtained for this problem are consequences of hybridizing the various known heuristics. Automatically revising the space constituted by combining these techniques to find the most adequate combination has received less attention. In this paper, we propose exploring the heuristics space for the vertex coloring problem using evolutionary algorithms. We automatically generate three new algorithms by combining elementary heuristics. To evaluate the new algorithms, a computational experiment was performed that allowed comparing them numerically with existing heuristics. The obtained algorithms present an average 29.97% relative error, while four other heuristics selected from the literature present a 59.73% error, considering 29 of the more difficult instances in the DIMACS benchmark.