The forest resources input–output model: An application in China

Understanding the state of forest resource utilization in China and correctly evaluating the role and function of forest resources in national economic development are essential for realizing balanced development of forests, the environment, and the economy. This is especially true given the present situation of increasingly scarce forest resources. Using data from Chinese forest industry statistical yearbooks, forestry development reports, and other documents, this paper examines the current state of forest resource utilization in China from the angle of combining quantities and values based on input–output tables. We show that demand for and input use of forest resources varies greatly across industrial sectors; the paper products and furniture manufacturing industries have the greatest direct consumption coefficient for timber use. When considering direct and indirect demand, it is clear that forest resources restrict different industrial sectors in diverse ways. These results provide an important set of reference values regarding the utilization of forest resources and coordinated industrial development in China.     

Can the problem of hybridization in threatened species be evaluated using a fieldwork research? A case study in snapdragons

Hybridization, natural or artificial, is considered disadvantageous for species biodiversity when it threatens the population integrity of endangered species. Frequently, studies investigating whether hybridization poses a legitimate risk to rare species are based on genetic data obtained in molecular biology laboratories. In this study, we used field research to approach the problem that hybridization could cause for the viability of a population of a rare species and to be able to propose the most appropriate initial conservation strategy. Specifically, using the model genus Antirrhinum, the reproductive barriers between the rare A. pulverulentum and its common congener A. litigiosum have been analysed under the reproductive isolation index (RI). A. pulverulentum had a high value of total RI, indicating that there are barriers to gene flow from A. litigiosum towards this species, and also had a high value for the intrinsic RI, reflecting a low inherent capacity for production of hybrid plants; in addition, the possibility of successful backcrosses between this species with hybrids produced from A. litigiosum ovules were low, given the high intrinsic RI of A. litigiosum. These data indicate the current existence of strong and permanent barriers to hybridization between the two species, suggesting that hybridization does not seem to be a serious problem for the conservation of A. pulverulentum in the studied population, nor for the near future. This study shows how the RI index can provide useful information for conservation purposes and proposes different management recommendations.     

Residual force enhancement contributes to increased performance during stretch-shortening cycles of human plantar flexor muscles in vivo

It is well known that muscular force production is history-dependent, which results in enhanced (RFE) and depressed (RFD) steady-state forces after stretching and shortening, respectively. However, it remains unclear if force-enhancing mechanisms can contribute to increased performance during in vivo stretch-shortening cycles (SSCs) of human locomotor muscles. The purpose of this study was to investigate whether RFE-related mechanisms contribute to enhanced force and power output during SSCs of the human plantar flexor muscles. Net ankle torques of fourteen participants were measured during and after pure isometric, pure stretch, pure shortening, and SSC contractions when the triceps surae muscles were electrically stimulated at a submaximal level that resulted in 30% of their maximum isometric torque. Dynamic contractions were performed over an amplitude of 15°, from 5° plantar flexion to 10° dorsiflexion, at a speed of 120° s⁻¹. External ankle work during shortening was 11.6% greater during SSCs compared to pure shortening contractions (p = .003). Additionally, RFD after SSCs (8.6%) was reduced compared to RFD after pure shortening contractions (12.0%; p < .05). It is therefore concluded that RFE-related mechanisms contribute to increased performance following SSCs of human locomotor muscles. Since RFD after SSCs decreased although work during shortening was increased, we speculate that the relevant mechanism lies outside actin-myosin interaction. Finally, our data suggests that RFE might be relevant and beneficial for human locomotion whenever a muscle is stretched, but this needs to be confirmed.     

A habitat colonisation model for spore-dispersed organisms—Does it work with eumycetozoans?

Spore productivities and establishment probabilities of eumycetozoans were estimated and compared with quantitative data obtained from field surveys, using series of cultures of a given substrate. Spore numbers per spore case were found to increase from one to four in protostelids to up to 10⁵–10⁶ in myxomycetes, whereas average spore size decreased slightly from 14.8 μm for protostelids to 10.3 μm in myxomycetes. Spore numbers of fructifications calculated from dimensions of spores and fruit bodies were in good agreement with direct counts carried out for six species of myxomycetes. A colonisation model is presented that estimates frequencies (as a percent of successfully colonized habitat islands), which is independent of a given density of spore rain and the sexual system of the species being considered. Whereas asexual species need a minimum spore rain of ca 0.7 spores per habitat island to reach a frequency of 50 %, this figure is at least 2.4-fold higher for sexual species, depending from the incompatibility system assumed. Data from cultures indicate that the maximum potential spore rain is usually three orders of magnitude higher than the minimum figure required to create the observed frequencies. Eumycetozoans seem to follow the evolutionary trends predicted by the model. Species with sexual reproductive systems produce often more spores than asexual ones; many morphospecies have sexual and asexual strains; and back-conversion from sexual to asexual reproduction occurs occasionally.     

Curculionid beetles in aborted flower buds and immature fruits of <Emphasis Type="Italic">Ceiba</Emphasis><Emphasis Type="Italic">pentandra</Emphasis> (Bombacaceae)

We determined the incidence of curculionid beetles of the genus Lonchophorus on aborted and not aborted flower buds and developing fruits of the tree Ceiba pentandra in southeastern Costa Rica. Beetle larvae were found in reproductive parts of all trees sampled trees. The frequency of beetle larvae was greater in aborted buds and immature fruits. A positive correlation between larvae development and flower bud development indicates that female oviposition occurred in an early flower developmental stage and time until bud abortion is variable. Weevil herbivory could be considered as one of the main factors that cause flower bud and fruit abortion in C. pentandra.

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Resumen Determinamos la incidencia de curculiónidos del género Lonchophorus en botones florales y frutos inmaduros tanto abortados como no abortados en el árbol Ceiba pentandra en el SE de Costa Rica. Las larvas de curculiónidos fueron encontradas en todos los árboles muestreados. La frecuencia de larvas fue mayor en botones y frutos abortados. Una correlación positiva entre el desarrollo larval y el desarrollo del botón indica que la oviposición ocurre en una fase temprana de este y que el tiempo hasta el aborto es variable. La herbivoría por larvas de curculiónidos puede ser uno de los factores más importantes en el aborto de botones y frutos inmaduros en C. pentandra.

     

How Can the Eco‐efficiency of a Region be Measured and Monitored?

The concept of eco-efficiency is commonly referred to as a business link to sustainable development. In this article, ecoefficiency is examined at a regional level as an approach to promoting the competitiveness of economic activities in the Finnish Kymenlaakso region and mitigating their harmful impacts on the environment. The aim is to develop appropriate indicators for monitoring changes in the eco-efficiency of the region. A starting point is to produce indicators for the environmental and economic dimensions of regional development and use them for measuring regional eco-efficiency. The environmental impact indicators are based on a life-cycle assessment method, producing different types of environmental impact indicators: pressure indicators (e.g., emissions of CO₂), impact category indicators (e.g., CO₂ equivalents in the case of climate change), and a total impact indicator (aggregating different impact category indicator results into a single value). Environmental impact indicators based on direct material input, total material input, and total material requirement of the Kymenlaakso region are also assessed. The economic indicators used are the gross domestic product, the value added, and the output of the main economic sectors of Kymenlaakso. In the eco-efficiency assessment, the economic and environmental impact indicators are monitored in the same graph. In a few cases eco-efficiency ratios can also be calculated (the economic indicators are divided by the environmental indicators). Output (= value added + intermediate consumption) is used as an economic indicator related to the environmental impact indicators, which also cover the upstream processes of the region's activities. In the article, we also discuss the strengths and weaknesses of using the different environmental impact indicators.     

Habitat availability,social attraction and nest distribution patterns in longear sunfish (Lepomis megalotis peltastes)

Synopsis Two forces, limited availability of preferred habitat and social attraction between conspecifics were hypothesized to explain nest aggregation in male longear sunfish. In the laboratory, males cluster their nests within a small segment of a much larger uniform area of nesting habitat. In the field, large areas of unused habitat suitable for nesting were found, suggesting that nesting aggregations are not formed as a result of limited preferred habitat. Males appear to be socially attracted during breeding, and social nesting presumably is a successful reproductive strategy for at least a portion of the population.     

Nesting habitat use and partitioning of three sympatric ninespine sticklebacks (genus <Emphasis Type="Italic">Pungitius</Emphasis>): implications for reproductive isolation

The nest site characteristics and distribution patterns of nests of three sympatric ninespine sticklebacks, the brackish- and fresh-water types and Pungitius tymensis, were investigated in the Shiomi River, eastern Hokkaido, Japan. In this river, most of the males of the brackish-water type were found to build their nests in the lower reach with higher salinity (mean 13.5‰) and water temperature (mean 13.3°C), whereas the males of the freshwater type and P. tymensis built their nests in the upper reach with lower salinity (mean 0.6 and 0.8‰, respectively) and water temperature (both mean 11.3°C). The ranges of their nesting areas, however, overlapped within the river, because the nests of the brackish-water type were widely distributed in the river. A comparison of the nest site characteristics in the area where nest overlapped indicated that there were no significant differences for all of five characteristics (the distance from the nest to the shore, the distance from the nest to the bottom, the distance to the nearest nest, the nest density and the amount of cover around the nest). Using canonical discriminant analysis, the nests of the three sticklebacks could not be distinguished using the five nest characteristics. These results suggest that habitat isolation through physical factors functions as an important mechanism of reproductive isolation between the brackish-water type and the other two sticklebacks.     

CyberKnife beam output factor measurements: A multi-site and multi-detector study

PurposeNew promising detectors are available for measuring small field size output factors (OFs). This study focused on a multicenter evaluation of two new generation detectors for OF measurements on CyberKnife systems.MethodsPTW-60019 microDiamond and W1 plastic scintillation detector (PSD) were used to measure OFs on eight CyberKnife units of various generations for 5–60 mm fixed cones. MicroDiamond and PSD OF were compared to routinely used silicon diodes data corrected applying published Monte Carlo (MC) factors. PSD data were corrected for Čerenkov Light Ratio (CLR). The uncertainties related to CLR determination were estimated.ResultsConsidering OF values averaged over all centers, the differences between MC corrected diode and the other two detectors were within 1.5%. MicroDiamond exhibited an over-response of 1.3% at 7.5 mm and a trend inversion at 5 mm with a difference of 0.2%. This behavior was consistent among the different units. OFs measured by PSD slightly under-responded compared to MC corrected diode for the smaller cones and the differences were within 1%. The observed CLR variability was 2.5% and the related variation in OF values was 1.9%.ConclusionThis study indicates that CyberKnife microDiamond OF require corrections below 2%. The results are enhanced by the consistency observed among different units. Scintillator shows a good agreement to MC corrected diode but CLR determination remains critical requiring further investigations. The results emphasized the value of a multi-center validation over a single center approach.     

Nutritional status influences reproductive seasonality in Creole goats: 1. Ovarian activity during seasonal reproductive transitions

The objective was to determine the effect of body energy stores, evaluated by a body mass index (BMI), and food intake (FI), on the length of the anovulatory period and ovarian activity during the seasonal reproductive transitions in Creole goats. Non-pregnant, non-lactating Creole goats (n = 28) were fed to induce two different BMI conditions: Greater (GBMI; n = 15), and Lesser (LBMI; n = 13). Each BMI group was divided into two sub-groups, which were either feed restricted (FR) or non-feed restricted (NFR). Goats in the NFR groups received a diet containing 100% of the daily maintenance requirements (basal diet), while restricted goats were subjected to alternated periods, receiving 100% (11 d) and 60% (10 d) of the basal diet, during the entire experimental period. The experiment started after does were treated to synchronize time of estrus. Serum progesterone was determined in samples obtained twice a week, and used as a criterion for determining ovulations. During the transition to the anovulatory period three transrectal ovarian ultrasonographic scans were performed in a sub-group of 12 goats (n = 3 for each treatment combination). The diameter of the largest follicle (LFD) and the total number of antral follicles ≥2 mm (TAF) were recorded. Ultrasonographic ovarian scans were performed at 21, 42 and 63 days after the beginning of the experiment, concurrently with the end of each feed restriction period. The variables of response associated with ovulation were not influenced by BMI or BMI × FI interaction. However, FI influenced length of anovulatory season, as the anovulatory period was 30 d longer (P < 0.05) in the FR group as compared with the NFR group. Independently of treatments, TAF and LFD decreased from the first to the third ultrasonographic ovarian scan (13.2, 10.8 and 4.4 follicles; 3.7, 2.7 and 2.3 mm). Nevertheless, in PER 1 the number of TAF was greater (P < 0.05) in the FR as compared with NFR group and the GBMI group had a larger LFD (P < 0.05) as compared to the LBMI group. It is concluded, that temporal restriction in feed intake could affect the time of cessation and initiation of ovulations during the periods of transition to seasonal anestrus and return to estrous activity, and increase the length of the anovulatory period. In addition, ovarian follicular development during transition into the anovulatory period is differentially influenced by food intake and the status of body energy stores.