Coarse woody debris mass and nutrients in forest ecosystems of Korea

Coarse woody debris (CWD) is an essential component of forests. However, quantification of both the mass and nutrient content of CWD within a given environment tends to be a fairly labor-intensive proposition that requires long-term studies to be conducted for viable data to be obtained. As a result, various aspects of CWD in forest ecosystems remain somewhat poorly understood. In this review, we have compiled all available estimates of CWD mass and nutrients from both coniferous and deciduous forests in Korea. The CWD mass data varied substantially by forest type, age, location, and sampling time, ranging from 1.5 to 24.5 Mg ha⁻¹, and for the amount (kg ha⁻¹) of nutrients in the CWD, ranging from 3.5 to 23.6 for nitrogen (N), 0.8 to 4.7 for phosphorus (P), 3.9 to 13.3 for potassium (K), 25.9 to 30.9 for calcium (Ca), 1.4 to 4.2 for magnesium (Mg), and 0.1 to 0.6 for sodium (Na). The mass of CWD transferred from live trees to the forest floor ranged between 0.1 and 4.9 Mg ha⁻¹ year⁻¹, and these values were roughly equivalent to 26–42% of the annual litterfall inputs (2.5–10.8 Mg ha⁻¹ year⁻¹) for mixed Quercus spp. forests within the relevant region. Annual nutrients inputs (kg ha⁻¹ year⁻¹) through CWD decomposition were 0.7–1.6 for N, 0.04–0.3 for P, 0.3–1.0 for K, 1.7–3.1 for Ca, and 0.1–0.3 for Mg. Consequently, these results revealed that the ecological value of CWD for C and nutrient cycling was relatively insignificant. However, only a limited number of studies have been conducted on CWD in different coniferous or mixed deciduous forests in the region. As a direct result of this paucity of data, further long-term studies on CWD mass and nutrients in a variety of forest types are required in order to be able to evaluate accurately the ecological value of CWD on biodiversity and physical properties in Korean forest ecosystems.     

Green tea catechins inhibit pancreatic phospholipase A(2) and intestinal absorption of lipids in ovariectomized rats

This study was conducted to examine whether the inhibition of intestinal lipid absorption by green tea is associated with the inhibitory effect of its catechins on pancreatic phospholipase A(2) (PLA(2)). PLA(2) activity was assayed by using 1,2-dioleoylphosphatidylcholine (DOPC), porcine pancreatic PLA(2) and catechins at varying concentrations (0.075-1.80 micromol/L). The amount of 1-oleoyl-2-hydroxyphosphatidylcholine liberated was determined by HPLC. The percentage of inhibition of PLA(2) by catechins at 0.6 micromol increased in the order of (-)-epicatechin (23.3%), (+)-catechin (CAT; 24.8%), (-)-epigallocatechin (25.7%), (-)-epicatechin gallate (39.7%) and (-)-epigallocatechin gallate (EGCG; 64.9%). In an in vivo study, ovariectomized rats with lymph cannula were infused intraduodenally for 8 h with a triolein emulsion containing [dioleoyl-1-(14)C]-phosphatidylcholine, DOPC, alpha-tocopherol (alphaTOH) and retinol (ROH) without (CAT0) or with CAT or EGCG. The lymphatic total (14)C-radioactivity was significantly lowered by EGCG (45.5+/-4.9% dose) compared with CAT (56.2+/-5.2% dose) and CAT0 (64.7+/-2.0% dose). The (14)C-radioactivity remaining in the small intestinal lumen and cecum was higher in EGCG (24.1% dose) than in CAT (9.5% dose) and CAT0 rats (9.0% dose). Significantly less (14)C radioactivity was incorporated into lymph triacylglycerol and cholesteryl ester in EGCG rats. The absorption of alphaTOH, used as a marker of extremely hydrophobic lipids, was significantly lower in EGCG (7.8+/-1.7 micromol) than in CAT (14.4+/-2.8 micromol) and CAT0 rats (16.8+/-2.1 micromol). The absorption of ROH was unaffected, whereas oleic acid output was lower in EGCG rats. The results show that EGCG inhibits the intestinal absorption of lipids, which is in part associated with its inhibition of phosphatidylcholine hydrolysis. Data suggest that EGCG may inhibit the absorption of other highly lipophilic organic compounds.     

Seasonal variation in soil CO<Subscript>2</Subscript> efflux in evergreen coniferous and broad-leaved deciduous forests in a cool-temperate forest,central Korea

We measured the soil surface CO₂ efflux (R _S) from January 2005 to December 2006 in two neighboring stands in Gwangneung Forest, central Korea: evergreen coniferous forest (Abies holophylla, stand A) and broad-leaved deciduous forest (Quercus-dominated, stand Q). Regarding seasonal variation, R _S rate was low during the winter and early spring months in each stand and peaked in late July [1170 (stand A) and 1130 (stand Q) in 2005, and 1000 (stand A) and 740 (stand Q) mg CO₂ m⁻² h⁻¹ in 2006]. R _S rate was higher in stand A than in stand Q during most of the growing season. The pattern of summer rainfall differed between 2005 and 2006. R _S rate for both stands was suppressed significantly by the droughts in June 2005 and September 2006. After the heavy rainfall of July 2006, R _S rate was lower than in July 2005 in both stands, but this decrement was much greater in stand Q than in stand A. In midsummer (August) 2006, under higher soil temperature (ST) and lower soil water content (SWC) conditions than in August 2005, R _S rate of stand A was lower than that in August 2005, whereas stand Q showed no marked change. The exponential relationship between ST and R _S accounted for approximately 91–97% of the R _S variability in each stand and in each year. In stand A, the application of a second-order polynomial function indicated a significant correlation between SWC and R _S when the soil was warm (ST > 15°C). Our results suggest that the seasonality of R _S is strongly affected by the pattern of summer rainfall even in an Asia monsoon climate regime. In addition, the vegetation type (i.e., evergreen coniferous forest vs. broad-leaved deciduous forest) plays a significant role in response of R _S to various environmental fluctuations such as drought, heavy rainfall, and hot-dry condition.     

Allergen-specific B cell subset responses in cow’s milk allergy of late eczematous reactions in atopic dermatitis

B cells have regulatory functions in immune responses. Antigen-specific responses of B cell subsets by allergen stimulation ex vivo were examined in milk allergy of late eczematous reactions. Eight milk allergy subjects and 13 milk tolerant subjects were selected by DBPCFC. PBMCs were stimulated by casein ex vivo and stained for B cell subsets using monoclonal antibodies. CD19+ B cells unchanged from 8.7 ± 3.8% to 8.0 ± 5.1% (p = 0.504, n = 8) in the milk allergy group and decreased in the milk tolerant group from 8.5 ± 3.2% to 5.0 ± 1.6% (p = 0.001, n = 13). The fraction of apoptotic B cells in B cells significantly decreased 4.4 ± 3.1% to 1.3 ± 0.4% (p = 0.027, n = 4) in the allergy group and insignificantly increased from 2.8 ± 0.6% to 5.4 ± 2.6% (p = 0.059, n = 6) in the milk tolerant group. CD5+ regulatory B1 cell% in B cells decreased in milk allergy subjects from 36.2 ± 5.0% to 31.0 ± 5.7% (p = 0.010) and unchanged in milk tolerant subjects from 41.6 ± 10.2% to 43.8 ± 10.0% (p = 0.413). IL-10 producing CD19+CD5+ regulatory B cell% in CD19+CD5+ regulatory B cells significantly decreased from 24.9 ± 6.5% to 13.8 ± 5.6% (p = 0.002, n = 5) by casein stimulation in milk allergy group and unchanged from 44.8 ± 11.3% to 43.9 ± 10.0% (p = 0.297, n = 5) in the milk tolerant group. B cell subset responses to IL-4 and IL-5 were also similar in both groups. B cell subset changes seemed to have diagnostic value. Exact immunologic roles of regulatory CD5+ B1 cells need further investigation.     

SEXUALLY MONOMORPHIC MATING PREFERENCES CONTRIBUTE TO PREMATING ISOLATION BASED ON SONG IN EUROPEAN GREEN LACEWINGS

When species are in intermediate stages of divergence, complicated patterns of reproductive isolation can arise among males and females of the incipient species. The Chrysoperla carnea group of green lacewings (Neuroptera: Chrysopidae) has recently experienced rapid speciation. They possess sexually monomorphic mating signals that were assumed to be important in mate recognition. Our objective was to compare patterns of reproductive isolation among five European species within the species complex as well as sex differences in mating strategies that contribute to those patterns. The species were in fact reproductively isolated based on mating signals. In addition, different species showed different degrees of responsiveness to conspecific signals, and those species that responded more frequently to conspecific signals were less discriminating against heterospecific signals. This suggests differences in mating strategies among species that may be related to population densities and heterospecific encounter rates. Sexual dimorphism in mating preference was apparent only in C. agilis , whose males were more responsive to all signals and less discriminating against heterospecific signals compared to females. Thus high variance in male quality may be characteristic of C. agilis , but not the remaining four species, whose male versus female mating strategies were similar.     

Carnitine short-chain acyltransferase in pea mitochondria

Carnitine acetyltransferase was shown to be present in pea-cotyledon mitochondria. Acetyl-carnitine may well be exported, without excessive energy loss, from mitochondrial matrix sites to extra-mitochondrial sites.     

Altered infant feeding patterns in boys with acquired nonsyndromic cryptorchidism

BACKGROUND : Genetic and environmental factors likely influence susceptibility to nonsyndromic cryptorchidism, a common disease presenting at birth or in later childhood. We compared cases and controls to define differential risk factors for congenital versus acquired cryptorchidism. METHODS : We compared questionnaire and clinical data from cases of congenital cryptorchidism (n = 230), acquired cryptorchidism (n = 182) and hernia/hydrocele (n = 104) with a group of healthy male controls (n = 358). Potential predictor variables (p < 0.2 in univariable analysis) were included in stepwise multivariable logistic regression models. RESULTS : Temporary (odds ratio [OR], 0.5; 95% confidence interval [CI], 0.4–0.8) or exclusive (OR, 0.6; 95% CI, 0.4–0.9) breastfeeding was reduced and soy formula feeding increased (OR, 1.8; 95% CI, 1.2–2.9) in acquired but not congenital or hernia/hydrocele groups. The highest risk estimates were observed for primary soy formula feeding with limited or no breastfeeding (OR 2.5; 95% CI, 1.4–4.3; adjusted OR, 2.7; 95% CI, 1.4–5.4) in the acquired group. Primary feeding risk estimates were equivalent or strengthened when multivariable models were limited to age greater than 2 years, full‐term or not small for gestational age, or Caucasian subjects. Pregnancy complications and increased maternal exposure to cosmetic or household chemicals were not consistently associated with either form of cryptorchidism in these models. CONCLUSIONS : Our data support reduced breastfeeding and soy formula feeding as potential risk factors for acquired cryptorchidism. Although additional studies are needed, hormonally active components of breast milk and soy formula could influence the establishment of normal testis position in the first months of life, leading to apparent ascent of testes in childhood. Birth Defects Research (Part A), 2012. © 2012 Wiley Periodicals, Inc.     

Mechanical Allodynia Circuitry in the Dorsal Horn Is Defined by the Nature of the Injury

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