bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis and Structure of a Highly Chlorinated C78: C78(2)Cl30
Authors: Troyanov Sergey I. , Tamm Nadezhda B. , Chen Chuanbao , Yang Shangfeng , Kemnitz Erhard
Published: July 2009

A highly chlorinated C78 fullerene, C78(2)Cl30, was obtained by the reaction of the isomer C78 (2) with SbCl5 in ampoules at 330–340 °C. Single‐crystal structure determination revealed that the C2v‐C78Cl30 molecule contains only isolated double bonds and aromatic benzenoid rings in the C78 carbon cage. Therefore, C78Cl30 represents the highest possible chlorination degree for C78 fullerenes obtained so far.
Three Lead(II) Complexes in One Coordination Polymer, [Pb(TpyCl)Cl][Pb(TpyCl)Cl2][PbCl3](CH3OH)
Authors: Saghatforoush Lotfali , Marandi Farzin , Pantenburg Ingo , Meyer Gerd
Published: July 2009

[Pb(TpyCl)Cl][Pb(TpyCl)Cl2][PbCl3](CH3OH) (1), a new coordination polymer of divalent lead with the ligand 4′‐chloro‐2,2′:6′,2"‐terpyridine (TpyCl), was obtained as single crystals by the branched tube method. The crystal structure contains three complexes, the cationic [Pb(TpyCl)Cl]+, the neutral [Pb(TpyCl)Cl2] and the anionic [PbCl3]–, which are connected through bridging chlorides and hydrogen bonds to a two‐dimensional coordination polymer. In all three complexes, the arrangement around the Pb2+ ion suggests the existence of a stereoactive lone pair.
A First and Homoleptic Rare Earth 3D‐Bipyrazolate MOF:{}^3_\infty[Eu(Me4BpzH)3(Me4BpzH2)]
Authors: Zurawski Alexander , Sieler Joachim , Müller‐Buschbaum Klaus
Published: July 2009

The homoleptic framework {}^3_\infty[Eu(Me4BpzH)3(Me4BpzH2)], Me4BpzH– = 3,3′,5,5′‐tetramethyl‐4,4′‐bipyrazolate anion, C10H13N4–, Me4BpzH2 = 3,3′,5,5′‐tetramethyl‐4,4′‐bipyrazole, C10H14N4, is obtained by a high‐temperature oxidation of the metal europium with a self consuming melt of 3,3′,5,5′‐tetramethyl‐4,4′‐bipyrazole above 300 °C. The framework structure initiates from a three‐dimensional linkage of europium atoms and bridging ligands that coordinate with one nitrogen atom of each aromatic ring linking η1:η1 through front and backside of the bicyclic ring system. The framework has a (4,8) topology and is the first example of a rare earth bipyrazolate. Thus, for the trivalent eightfold by nitrogen atoms coordinated europium, a sterically rather crowded ligand with four methyl groups is able to yield a 3D‐framework. The crystal structure was refined from systematically eightfold twinned crystals as meroedric fourfold twins with a subsequent racemic twinning of the fourfold twin individuals.
Attempted Reduction of Divalent Rare Earth Iodo Aminopyridinates
Authors: Qayyum Sadaf , Noor Awal , Glatz Germund , Kempe Rhett
Published: July 2009

Rare examples of amido‐iodo complexes of selected divalent lanthanides can be synthesized by using deprotonated Ap*H {Ap*H = 2,6‐diisopropylphenyl)‐[6‐(2,4,6‐triisopropylphenyl)‐pyridin‐2‐yl]‐amine} as a stabilizing ligand. Reaction of [Ap*K]n with [LnI2(thf)n] (Ln = Eu, Yb, n = 4,5) in THF leads to [Ln(Ap*)I(thf)2]2 (Ln = Eu, Yb). An attempted reduction of these divalent heteroleptic complexes with KC8 to synthesize complexes containing an unsupported Ln–Ln bond resulted in the formation of [Ln(Ap*)2(thf)2]. These lanthanide complexes were characterized by X‐ray structure analysis.
Melanomas display increased cytoprotection to hypericin‐mediated cytotoxicity through the induction of autophagy
Authors: Davids Lester M. , Kleemann Britta , Cooper Susan , Kidson Susan H.
Published: July 2009

Photodynamic therapy (PDT) as a regime for melanoma is of limited success due to factors such as the efficacy of the photosensitizer used, penetration depth and the presence of pigment. We characterised a pigmented and an unpigmented melanoma cell line with respect to their phenotypes. Cell viability was assessed after exposure to hypericin, a UVA‐activated photosensitizer. Exposure to 3 μM activated hypericin induced a cytoprotective (autophagic) response from both cell lines. However, the pigmented cells accumulated a large amount of glycogen in their cytoplasm. We hypothesise that the treatment induces an initial cytoprotective response through autophagy, but with increased stress results in a different mode of cell death in pigmented melanoma cells from unpigmented cells. These results indicate that hypericin‐PDT could be an adjuvant therapy for melanoma.
Changes in quality of life following cognitive-behavioral group therapy for panic disorder
Authors: Rufer M. , Albrecht R. , Schmidt O. , Zaum J. , Schnyder U. , Hand I. , Mueller-Pfeiffer C.
Published: July 2009

Background

Data about quality of life (QoL) are important to estimate the impact of diseases on functioning and well-being. The present study was designed to assess the association of different aspects of panic disorder (PD) with QoL and to examine the relationship between QoL and symptomatic outcome following brief cognitive-behavioral group therapy (CBGT).

Methods

The sample consisted of 55 consecutively recruited outpatients suffering from PD who underwent CBGT. QoL was assessed by the Medical Outcomes Study 36-item Short-Form Health Survey (SF-36) at baseline, post-treatment and six months follow-up. SF-36 baseline scores were compared with normative data obtained from a large German population sample.

Results

Agoraphobia, disability, and worries about health were significantly associated with decreased QoL, whereas frequency, severity and duration of panic attacks were not. Treatment responders showed significantly better QoL than non-responders. PD symptom reduction following CBGT was associated with considerable improvement in emotional and physical aspects of QoL. However, the vitality subscale of the SF-36 remained largely unchanged over time.

Conclusions

Our results are encouraging for cognitive-behavior therapists who treat patients suffering from PD in groups, since decrease of PD symptoms appears to be associated with considerable improvements in QoL. Nevertheless, additional interventions designed to target specific aspects of QoL, in particular vitality, may be useful to enhance patients’ well-being.
Extensibility of the Hamstrings Is Best Explained by Mechanical Components of Muscle Contraction, Not Behavioral Measures in Individuals With Chronic Low Back Pain
Authors: Marshall Paul W.M. , Mannion Jamie , Murphy Bernadette A.
Published: July 2009

Objective

To examine the relationship between hamstring extensibility by use of the instrumented straight leg raise; mechanical components of muscle contraction, including muscle recruitment, passive torque measures of tissue stiffness, and eccentric strength; and self‐reported measures of pain and disability.

Design

Cross‐sectional study.

Setting

University laboratory.

Participants

Twenty‐one individuals with chronic nonspecific axial lower back pain and 15 healthy control subjects.

Assessment

Instrumented straight leg raise, concentric and eccentric hamstring strength, self‐reported measures of pain, disability, fear avoidance, general health and well‐being

Main Outcome Measurements

Objective measures included hamstring extensibility, hamstring muscle stiffness, absolute and relative concentric/eccentric strength, concentric/eccentric strength ratios. Self‐reported measures included Oswestry disability index, visual analog pain scale, fear avoidance beliefs, and general health and well being.

Results

Patients with lower back pain had lower range of motion, greater changes in muscle stiffness, and impaired concentric‐to‐eccentric strength levels. Stepwise regression identified measures of stiffness as significantly predicting hamstring extensibility (adjusted r2 = 0.58, F = 23.76, P < .001). Self‐reported measures were not associated with extensibility. Gender differences were noted for passive stiffness and absolute strength. For women, later onset of the medial hamstrings also was associated with greater hamstring extensibility.

Conclusions

Decreased extensibility of the hamstrings was associated with increased passive stiffness during the common range of motion (20 to 50°). Impaired stretch tolerance is associated with actual mechanical restriction, not behavioral measures indicating increased pain or fear‐avoidant behavior. With no relationship to actual disability and contradictory findings in the literature for the relationship of the hamstrings to the mechanics of the low back, it is unclear whether decreased hamstring extensibility should be targeted in rehabilitation programs for axial lower back pain.
IN VITRO AND ECUADOR-FIELD PERFORMANCE OF VIRUS-TESTED AND VIRUS-INFECTED PLANTS OF TROPAEOLUM TUBEROSUM
Authors: SORIA RE S. , TABOADA C. , GONZALEZ R. VEGA , EVANS T. , DAMSTEEGT V. D. , KITTO S.
Published: July 2009

Ecuadorean mashua (Tropaeolum tuberosum) germplasm has been found to be widely infected with the potyvirus Tropaeolum mosaic virus (TropMV). The objective of this research was to produce virus-tested (VT) germplasm to compare growth in vitro and in the field with virus-infected (V) germplasm. Twenty-three of 25 apical dome-derived clones tested free of virus based on bioassays using Nicotiana benthamiana and Chenopodium quinoa. In vitro-generated plant tissue was just as effective for determining VT status as greenhouse-generated plant tissue. Genotype rather than virus-infection status appeared to have a greater effect on in vitro proliferation. There were no differences in in vitro rooting among the genotypes or between the VT clones compared to the V clones, with at least 90% of the microcuttings rooting. However, rooted microcuttings of V clones were taller than rooted microcuttings of VT clones. Plants were readily re-established in a greenhouse at the USDA, Foreign Disease-Weed Science Research Unit at Fort Detrick, USA. In field experiment 1, ca. 75% of the plants survived field transplanting and VT plants of genotype 1147 had greater tuber weight (928 g) than V plants (235 g). In field experiment 2, plant mortality was high one month after field transplanting. Genotypes 1093 (59%) and 1141 (54%) had higher survival than genotype 1147 (44%); however, survival did not differ between the VT (46%) and V (59%) plants of all genotypes. No differences were noted in field performance for the three genotypes after 10 months of growth. Although overall tuber yield among the V, VT and VTR (reinfected-VT plants) did not differ, V plants produced big tubers that weighed more than those from VT plants. Thirty-three percent of the VT plants became reinfected and 42% of the V plants tested negative after 10 months in the field based on double-antibody-sandwich ELISA.
Audit of frequent attendees to an ENT emergency clinic
Authors: Fishpool S J C , Stanton E , Chawishly E-K , Hicklin L A C
Published: July 2009

Objective:

To audit the number of patients attending an ENT emergency clinic more than twice in the same clinical episode.

Method:

A completed audit cycle. The inclusion criterion for the retrospective arm was patients who had attended the ENT emergency clinic more than twice between 1 September to 30 November 2007. Data were analysed and interventions implemented. The re-audit, using the same inclusion criteria, was done between 1 March to 31 May 2008.

Results:

The initial audit found that 38 patients were seen more than twice in the ENT emergency clinic, giving rise to 81 ‘excess’ clinic appointments. After intervention, the re-audit identified 19 patients who were seen more than twice in the ENT emergency clinic, giving rise to 24 ‘excess’ clinic appointments.

Conclusion:

By insisting that patients seen more than twice in the ENT emergency clinic were reviewed by a senior clinician, and by introducing a management guideline for acute otitis externa, we reduced excess clinic appointments by 70 per cent.
Differences in airstream and posterior place of articulation among Nǀuu clicks
Authors: Miller Amanda L. , Brugman Johanna , Sands Bonny , Namaseb Levi , Exter Mats , Collins Chris
Published: July 2009

This paper describes the consonant inventory of the endangered southern African language Nǀuu. Our novel approach to segment classification accounts for all 73 Nǀuu consonants with just four phonetic dimensions (place, manner, phonation, airstream) and does away with the phonetically empty categoryclick accompaniment. We provide ultrasound data showing that the posterior constrictions in clicks are not produced at the ‘velar’ place of articulation, and that posterior place differs with anterior place. We therefore argue for a terminological shift fromvelarictolingualairstream mechanism. Our data also show that the posterior place of articulation is the same in Nǀuu's five lingual ([⊙ ǀ ǃ ǁ ǂ]) and linguo-pulmonic ([]) stops. We argue that the difference between these segment classes is best captured in terms of airstream, not place. Plain clicks use only the lingual airstream, while linguo-pulmonic segments are airstream contours, in which the transition to the pulmonic airstream occurs within the segment rather than at its boundary. Our evidence suggests that the contrast between ‘velar’ and ‘uvular’ clicks proposed for the related language ǃXóõ is likely also one of airstream and that a contrast solely in terms of posterior place would be articulatorily impossible.
The phonetics of register in Takhian Thong Chong
Authors: DiCanio Christian T.
Published: July 2009

The Chong language uses a combination of different acoustic correlates to distinguish among its four contrastive registers (phonation types). Electroglottographic (EGG) and acoustic data were examined from original fieldwork on the Takhian Thong dialect. EGG data shows high open quotient (OQ) values for the breathy register, low OQ values for the tense register, intermediate OQ values for the modal register, and rapidly changing high to low OQ values for the breathy-tense register. Acoustic correlates indicate that H1-A3 best distinguishes between breathy and non-breathy phonation, but measures like H1-H2 and pitch are necessary to discriminate between tense and non-tense phonation. A comparison of spectral tilt and OQ measures shows the greatest correlation between OQ and H1-H2, suggesting that changes in the relative amplitude of frequencies in the upper spectrum are not directly related to changes in the open period of the glottal cycle. OQ is best correlated with changes in the degree of glottal tension.
The alignment of L + H* pitch accents in Persian intonation
Authors: Sadat-Tehrani Nima
Published: July 2009

This paper investigates how the tonal targets of rises in Persian are phonetically realized in relation to the segmental string. Three types of cliticized Persian Accentual Phrases (APs) are instrumentally compared with one another: high-boundary-toned pre-nuclear APs, low-boundary-toned nuclear APs, and low-boundary-toned contrastive focus APs. The results show that the valley is always aligned with the consonant preceding the stressed vowel, but the alignment of the peak is with the consonant following the stressed vowel if the AP boundary tone is low, and with the following vowel if it is high. The duration of the focus AP is greater than that of the other two. The pitch excursion of the focus AP is significantly greater than that of the nuclear type. This difference is caused by different peak heights. While pre-nuclear and nuclear APs can be phonologically represented by L + H*, focus APs, which are pragmatically different, warrant a distinct pitch accent, namely L + ^H*. The systematic alignment of the L and the H, and the variability of the time and slope of the rise support the view that pitch targets rather than pitch movements are the fundamentals of Persian intonation.
Response to W. J. Barry & J. Trouvain, Do we need a symbol for a central open vowel?JIPA38 (2008), 349–357
Authors: Recasens Daniel
Published: July 2009

In the paper ‘Do we need a symbol for a central open vowel?’, William Barry and Jürgen Trouvain unveil possible gaps in the IPA chart while positing the need for having three basic phonetic symbols for transcribing open vowels of the world's languages. The main point raised by the authors is that the phonetic quality ofain languages with a single open vowel is somewhere in between that of the open front and back vowels in more complex vowel systems. They exemplify this point by referring to the open vowel of the Spanish wordgata, which is usually transcribed with the symbol [a] in spite of being more central than Cardinal Vowel 4. Several possible solutions are proposed: adding small capital A or barredafor the open central vowel to the already existing symbols [a] and [ɑ]; keeping [ɑ] for the open back vowel, moving the symbol [a] to the open central vowel position, and having either [æ] or small capital A as symbols for the open front vowel. As argued below, I do not believe that three IPA phonetic symbols are really needed for the transcription of different variants ofa.
Response to W. J. Barry & J. Trouvain, Do we need a symbol for a central open vowel? JIPA 38 (2008), 349–357
Authors: Ball Martin J.
Published: July 2009

I leave to others the argument as to whether there is sufficient justification to add a central open vowel symbol to the IPA. Rather, in this response, I would like to comment on the various proposals for what such a symbol should be outlined in Barry & Trouvain (2008). I will not be following the original ordering of suggestions in the article, but start with the proposals to redefine current symbols.
Mah Meri
Authors: Kruspe Nicole , Hajek John
Published: July 2009

Mah Meri (ãʔ məri) belongs to the Aslian branch of Mon-Khmer within the Austroasiatic family. It is classified as a Southern Aslian language, along with Semelai, Semoq Beri and Temoq (Benjamin 1976). Mah Meri is spoken by the Mah Meri ethnic group in scattered settlements along the south-west coast of the Malay peninsula stretching from Port Kelang to Bukit Bangkong, Sepang in the state of Selangor, Malaysia. The island of Sumatra lies a short distance away across the Malacca Strait. The Mah Meri language, which may have as many as 2,185 speakers, has no written tradition and is highly endangered.
Land types and vegetation in the Luuq district of south-western Somalia
Authors: Wieland Ronald G. , Werger M. J. A.
Published: July 2009

A land use survey involving land typing and vegetation classification was conducted within the Luuq District Refugee Area (200,000 ha) in south-western Somalia. Average rainfall and annual temperature of the area are 310 mm and 30.5° C. The area is composed of limestone and basalt uplands, gypsiferous and alluvial interplains, and ancient and recent alluvial terraces of the Juba River.

Land types were identified by aerial photo survey and ground observation and mapped on a 1:100,000 scale LandSat Satellite (colour) Image. Soil types were classified according to the method used by the US Department of Agriculture, Soil Conservation Service. Vegetation was sampled according to the Braun-Blanquet approach in 52 releves located within previously mapped land types, and analysed using the traditional phytosociological methods and the DECORANA and TWINSPAN computer programs. The results of these methods are compatible with one another. Most community types identify distinct land types: basalt and limestone uplands, gypsum and alluvial interplains, and depressions and gentle rises of the Juba River terrace.

Commiphora and Acacia species dominate the open thorny bushland. They are mostly medium-sized shrubs and trees, 1 to 4 m in height. There is little herbaceous ground cover except in depressions and drainageways. Total shrub and tree cover averages 34%. Due to the large influx of refugees, there has been excessive cutting for fuelwood and construction material and notable bushland converted to cropland. Degradation of the vegetation and soils is prominent and is most evident on the upper and lower terraces of the Juba River.
Movement and spatial distribution of the Nile rat (Arvicanthis niloticus) in Kenya
Authors: Delany M. J. , Monro R. H.
Published: July 2009

The movement and spatial distribution of marked Nile rats, Arvicanthis niloticus, was traced through phases of a low density population from January to August 1981, a rapidly growing population from September to January 1982, and a high and declining post-reproductive population from February to April 1982. Apart from late in the population cycle there was considerable movement, interchange and establishment of new ranges. As the population increased individual ranges became smaller. The rats apparently preferred field edges and did not favour the fields themselves. Females frequently established themselves at certain sites where they produced their litters; some of the offspring remained with the mother in the warren. There is also evidence that ousiders of both sexes joined these warrens. Males were generally more wide-ranging than females. Agricultural practices, e.g. mowing and trampling by cattle, influenced the rats preparedness to remain within a particular location. Exploitation of all the available habitat took several months to achieve.
Selection of second-growth woodlands by frugivorous migrating birds in Panama: an effect of fruit size and plant density?
Authors: Martin Thomas E.
Published: July 2009

I provide evidence that migrating birds concentrate in tropical second-growth woodlands due, in part, to a greater abundance of small fruits. Migrant birds markedly increased in abundance during spring migration in late March in a young (approximately 25 years old) second-growth woodland in Panama. Migrant abundance and diversity was greater at mist-net level on the second-growth site than in nearby old forest. Diversity of canopy migrants also was greater in the young woodland than in an old second-growth forest. Thus, many migrant species appear to select young second-growth during spring migration in central Panama. Degree of frugivory by many migrant species was greater during migration than earlier in the dry season. Most migrants selecting the second-growth site were highly frugivorous and migrants accounted for most of the visits to common fruit species, but use of fruit trees appeared to be influenced by fruit size relative to gape width. Most migrants have mouths that are better suited to eating the small fruits predominating in young forest than the larger fruits characteristic of old forest. Abundances of bird-dispersed fruit plants and, particularly, those fruit species known to be eaten by migrants were greater in young than in old forest. The high food demands of migrating birds added to the high degree of frugivory of most migrants selecting second-growth forest suggests that the abundance of small fruits in second-growth may be a strong cause for habitat selection during migration.
Pollination of Dendrobium infundibulum, Cymbidium insigne (Orchidaceae) and Rhododendron lyi (Ericaceae) by Bombus eximius (Apidae) in Thailand: a possible case of floral mimicry
Authors: Kjellsson Gösta , Rasmussen Finn N. , Dupuy David
Published: July 2009

The orchids Dendrobium infundibulum and Cymbidium insigne are pollinated by the bumblebee Bombus eximius, which also pollinates the ericaceous shrub Rhododendron lyi, A study of the three plants and the bumblebee in maquis-like mountainous vegetation in northern Thailand suggests that they form a floral mimicry system with two mimics (the orchids) to one model (R. lyi). The flowers of the two orchid species offer no food reward to pollinators. Flowers of the three species show definite morphological and visual resemblance, and the species overlap to a great extent in flowering phenology and habitat Mimic flowers were much less numerous than model flowers, which occurred abundantly in the area. The rate of pollinaria removal was very low in both orchid species, resulting in a relatively small percentage of fruit set, especially in D. infundibulum. Infrequency of pollinator visits was, however, somewhat counterbalanced by long-lasting flowers. The pollinaria of the two orchid species are differently positioned on the bee, hence interference between the different reproductive systems is minimized. This is the first report which indicates floral mimicry from tropical Asia.
Effects of light regime on the growth and physiology ofPentaclethra macroloba(Mimosaceae) in Costa Rica
Authors: Oberbauer Steven F. , Strain Boyd R.
Published: July 2009

Seedlings ofPentaclethra macroloba(Willd.) Kuntze, a dominant, shade-tolerant species of tropical moist forest in Costa Rica, were raised under three light conditions to assess their acclimatization and growth responses to irradiance. The light environments used were full sun, partial shade (25% of full sun), and full shade (1% of full sun). To test the effect of a sudden change in light level such as would occur in the event of a treefall gap, the seedlings in the above conditions were switched between environments after two months and grown for an additional 1.5 months. Plants in full sun and partial shade had similar total weight; switching between the two environments had no effect on biomass. Plants switched from full sun and partial shade to full shade had negative growth as a result of negative CO2, flux and leaf abscission. Plants transferred from full shade to full sun had lower growth rates than those switched from full shade to partial shade because of severe leaf damage in full sun. The previous environment significantly affected the response of most growth and size characteristics to the present environment. Maximum photosynthesis changed only 30% in response to light level during growth. However, large changes in other photosynthetic and structural characteristics were found. Leaves developed in full shade had lower respiration, leaf thickness, and stomatal density and higher apparent quantum yield, specific leaf area, and chlorophyll content than leaves from full sun. Osmotic potentials were similar between treatments. Despite only small changes in maximum photosynthesis, acclimatization to extreme shade or sun rendered leaves unsuitable for large changes in environment. Consequently, in the event of a large treefall gap, plants already present in the understory will require a substantial period of adjustment before they respond to the increase in light.
On the leaf litter community of the Amazonian blackwater stream Tarumazinho
Authors: Henderson P. A. , Walker I.
Published: July 2009

A study of the benthic leaf litter community of the Tarumazinho, a central Amazonian stream (03° S, 60° W) is presented. This small tributary of the Rio Negro is of the blackwater type with a very low nutrient content. The sampling stations were towards the mouth of the tributary where it flowed through annually inundated forest and the work was carried out during the low water season. Previous studies concluded that these acid waters were of very low productivity and held impoverished faunas. However, this study showed that leaf litter banks held a diverse aquatic community of unexpectedly high biomass. This was because the banks supplied food and shelter and were available during the low water period when other habitats had dried out. The macrofauna was dominated by fish and shrimps. From an examination of gut contents a food web was produced. Primary consumers were found to take mainly detritus and fungi and it was concluded that allochthonous inputs were the main source of energy and nutrients. No feeding specialists were found and all the predators took prey from more than one trophic level.
Sporadic food competition with the African honey bee: projected impact on neotropical social bees
Authors: Roubik David W. , Moreno J. Enrique , Vergara Carlos , Wittmann Dieter
Published: July 2009

Bee colonies in lowland forest in Panama were monitored for pollen and nectar harvest, pollen species utilization and nectar quality and quantity per returning forager. Despite sharing most pollen resources and nectar of the same quality with 20 introduced colonies of the African honey bee (Apis mellifera), native stingless bees of 12 species were largely unaffected by its activity. Pollen and nectar harvested by the honey bees were 10–200 times that procured by 17 stingless bee colonies. This discrepancy in total harvest and general lack of competitive effect is explained by a honey bee foraging area over 10 times that of the native bees, and apparent foraging shifts to escape competition with honey bees, thus reduced potential overlap in foraging sites.

Seven cases of direct resource competition for pollen or nectar were documented, out of 31 tests. Rare periods of intensive harvest were diminished by competing African honey bees. Such harvest peaks lasted for only a few hours in 13 days of observation. Despite average duration of 4% foraging time for each species, peaks included as much as 51% total harvest. Calculations based upon colony populations, food stores and flight range show that if African honey bees persist at a density of 1 colony per km2, colonies of some stingless bee species may disappear after 10 years. Their chances of escaping food competition by taxonomic specialization on flowers seem slight.
An experimental study of seed ingestion and germination in a plant-animal assemblage in Ghana
Authors: Lieberman Milton , Lieberman Diana
Published: July 2009

Fleshy fruits collected from abundant woody plants on the Accra Plains, Ghana, were fed to frugivorous species common in the area. Seeds of each plant species were retrieved from each frugivore species for germination trials, and ingested seeds compared to fresh seeds in germination percentage and rapidity. Altogether 85 plant X animal feeding combinations were attempted. In 73% of trials, ingestion did not affect germination percentage; the remain-ing trials were about equally divided between significant increases and decreases. Ingested seeds had significantly faster germination in 12%, and significantly slower germination in 8%, of the trials. Germination percentages in all samples of fresh seeds (= 37%) did not differ signifi-cantly from those ingested seeds (= 31%).

There was a significant association between the effect of ingestion on both germination rapidity and percentage (significantly increased, decreased, or neither) and the plant species involved; there was no such association between the effect of ingestion and the animal species. Animals had inconsistent and frequently negligible effects on germination. Two-way analyses of variance (plants X animals) of germination percentage and of germination improvement showed that plant species were a significant source of variation and animal species were not. The fleshy-fruited plants of this assemblage are not generally dependent upon animals for successful germination of their seeds.
Temperature regulation and water balance of day-active Zophosis congesta beetles in East Africa
Authors: Røskaft Eivin , Zachariassen Karl Erik , Maloiy Geoffrey M. O. , Kamau John M. Z.
Published: July 2009

East African tenebrionid beetles of the species Zophosis congesta are active on sun-exposed surfaces in dry habitats during the hottest part of the day, when most other animals have retreated to protected areas. They remain on the surface at ambient temperatures up to 65°C which is 15°C above their highest tolerated body temperature. The beetles appear to regulate their body temperature behaviourally. They frequently rest and cool in the shade, and after each cooling period they remain on the sun-exposed surface until the heat influx from the environment has caused the body temperature to rise close to the lethal level. They have relatively low rates of transpiratory water loss, and appear unable to depress their body temperature by means of evaporative heat loss. The rate of metabolic production of water amounts to only about 20% of the rate of transpiratory water loss. Thus, the beetles depend strongly on water intake from dietary sources. The advantage of this type of activity pattern is probably avoidance of predators.
Profiles of CO2 concentration and δ13C values in tropical rain forests of the upper Rio Negro Basin, Venezuela
Authors: Medina Ernesto , Montes Gustavo , Cuevas Elvira , Rokzandic Zarko
Published: July 2009

Concentration of CO2, above and below the soil surface and δ13C values of plant tissues, soil litter and organic matter were measured in a caatinga forest of the upper Rio Negro basin in southern Venezuela. CO2, concentrations near the forest floor were consistently higher than in the atmosphere. CO2, gradient in the soil was very steep probably because of the poor aeration in this flood-prone forest. δ13C values of plant tissues showed a clear pattern with lower values in the ground herbaceous plants and under-canopy trees. Tree seedlings showed δ13C values similar to the upper-canopy trees indicating their dependence on reserves carried in the seed from the mother tree. Decomposing litter and soil organic matter also showed δ13C values similar to the upper-canopy trees. It is suggested that lower δ13C values of the shade flora result primarily from the assimilation of CO2, depleted in δ13C originating from soil respiration. Probable effects of low light intensity and physiological factors are discussed.
Studies of birds in a semi-arid area of Kenya. III The use of ‘Timed Species-counts’ for studying regional avifaunas
Authors: Pomeroy Derek , Tengecho Beatrice
Published: July 2009

‘Times Species-counts’ are a simple method of comparing the avifaunas of extensive areas by sampling representative habitats. The method has been evaluated in south central Kenya but could be applied to most terrestrial regions of tropical Africa. The essential feature is that the observers move anywhere within a sample site of about 1 km2, recording all of the species seen in a fixed time, e.g. 1 h.

Counts are made in all seasons and at various times of day. Reasonable estimates of the total number of species in an area can be derived from a series of 15 counts, but such estimates tend to be low in non-forested habitats because ‘wanderers’ (non-resident species) continue to be recorded almost indefinitely. Open sites have far fewer species than well-wooded areas. The numbers of resident species in non-forested terrestrial habitats is related both to the amount of woody vegetation and to a measure of plant growth. However, total species numbers seem to depend solely on the amount of woody vegetation. Road counts, from a vehicle, were compared to those made on foot. They are less satisfactory, especially for cryptic species.
Soil nutrient availability, root symbioses and tree species composition in tropical Africa: a review
Authors: Högberg Peter
Published: July 2009

Relations between soil nutrient availability, the occurrence of root symbioses and tree species composition in tropical Africa are discussed in the light of new evidence. Transects from humid areas at the equator towards the deserts can be summarized as follows:

High availability of nitrogen, low availability of phosphorus, low pH and aluminium toxicity probably restrict the competitiveness of nitrogen-fixing species in the forests on highly weathered and leached soils in humid west and central Africa. Ectomycorrhizal species attain dominance in species-poor forests on the soils poorest in phosphorus, while species with vesicular-arbuscular (VA) mycorrhiza form diverse forests on more fertile soils. Nitrogen-fixing species, which mostly are VA mycorrhizal, are more common in woodlands, where nitrogen is lost in grass fires, than in forests, which have a more closed nitrogen cycle. Low availability of phosphorus, however, limits the growth of nitrogen-fixing species in moist savannas. Ectomycorrhizal species are dominant, possibly because of a competitive advantage conferred by the large storage capacity of the fungal mantles under conditions of discontinuous nutrient supply. Nitrogen-fixing species become more abundant towards drier areas with an increase in soil phosphorus and a decline in soil nitrogen. These conditions culminate at the desert fringe, where nitrogen-fixing species reach their most conspicuous development.

It is concluded that soil nutrient availability and root symbioses interact and strongly affect the composition of vegetation communities.
The freshwater lakes of Papua New Guinea: an inventory and limnological review
Authors: Chambers M. R.
Published: July 2009

A survey of the 1:100,000 topographic maps of Papua New Guinea revealed that there are about 5383 freshwater lakes in the country. They range in size up to 647 km2but the majority are less than 10 ha. They are found at all altitudes to over 4000 m but most are situated below 40 m in the floodplains of the Fly, Sepik and Aramia rivers. The majority of lakes are undoubtedly shallow but depths range up to 360 m. The lakes were formed in at least 20 different ways but the majority by fluviatile action. The few data on chemical and physical conditions suggest that most lakes are chemically poor with low light penetration and low pH values. With the possible exception of the macrophytes the fauna and flora of the lakes are virtually unstudied, particuarly from a quantitative aspect. Most lakes are probably polymictic.
Forest composition and inferred dynamics in Jengka Forest Reserve, Malaysia
Authors: Ho C. C. , Newbery D. McC. , Poore M. E. D.
Published: July 2009

1211 trees of 3 ft (0.91 m) girth or more were enumerated in 288 1-ch2(about 400 m2) quadrats forming a 11.7 ha plot on the mainly Segamat soil series, Jengka Forest Reserve, Peninsular Malaysia, in 1964. Of the 261 taxa, 84% were identified to species. Five per cent of the area was of the permanently wetter Akob soil series. The plot was topographically flat and lay about 3 km west of the plot on the Batu Anam soil series, described in an earlier paper. Data on the chemical composition of the three soils are summarized here from a survey in 1967.

The vegetation on the Segamat series is of theShorea-Dipterocarpustype of lowland dipterocarp forest. It has an unusually high abundance of the Euphorbiaceae (25% of trees) and a clear dominant species,Elateriospermum tapos. E. tapos, which regenerates profusely in the shade, grows up in small gaps and is strongly clumped, and appears well suited to the very friable, relatively nutrient-rich soil of the Segamat series, with lower soil-water holding capacity especially in dry periods.

Forest on the Segamat series is floristically very different from that on the Batu Anam series. This is most likely due to large differences in soil properties, the latter being of lower clay content, less nutrient-rich and, having a greater soil-water holding capacity at least in dry periods. It was dominated by Dipterocarpaceae.

Classification of quadrats on the Segamat series highlighted four classes; vegetation of the mainE. tapos-dominated type on relatively dry soil (54% of plot area), vegetation on the wet Akob soil (21%), an association of shade-tolerant, mainly understorey trees beneath non-E. tapos-associated emergents (11%), and an association of long-lived, light-demanding pioneer trees of late-successional stages (11%); 3% of plot had no enumerated trees. Ordination showed that the plot was largely homogeneous with respect to edaphic factors but clearly displayed stages in forest succession.

The possible dynamics of the Segamat forest are inferred in terms of species autecology. Two hypotheses are advanced to explain the composition of the Segamat forest: (a) a dynamic equilibirum, (b) a non-equilibrium recovery from a recent catastrophe. The latter was thought more likely. Compared with the more benign Batu Anam environment, where co-dominants might be ‘ecologically equivalent’, the more selective soil conditions on the Segamat leads to reduced equivalence, with accidents of regeneration playing a smaller role in the local distribution of the most abundant species.
A survey of food-plant utilization by Hemiptera (Insecta) in the understorey of primary lowland rain forest in Sulawesi, Indonesia
Authors: Hodkinson I. D. , Casson D. S.
Published: July 2009

The study was conducted in tropical lowland forest in the Dumoga Bone National Park, Sulawesi, Indonesia. It sought (a) to establish the typical densities of sap-sucking Hemip tera, (b) to quantify the intensity of Hemiptera feeding on leaves, and (c) to investigate, using multivariate techniques, the relationships between Hemiptera density and/or feeding damage and a range of leaf or plant characteristics. Only 3% of shrubs examined had colonial Hemiptera feeding on growing shoots. Feeding punctures on leaves were common but the insects which produced them such as the Cicadellidae and various Heteroptera were scarce. Coccoidea and Aleyrodoidea were the dominant and ubiquitous Hemipterans, feeding primarily on the surface of the leaves. Psylloidea were relatively rare and Aphidoidea were not recorded. For the complete data set, which included all leaves examined, there were few significant correlations, either singly or in combination, between the various measures of insect abundance and the state of the 17 leaf characteristics recorded. However, when the data for young leaves were extracted there was evidence to suggest that the number of feeding punctures cm−2of leaf and the number of coccids cm−2of upper leaf surface increased rapidly to a maximum as the young leaf aged and certain characters changed accordingly. Other more stable leaf characteristics such as hairiness, spininess, glossiness, etc. explained only a small additional amount of the total variance in Hemiptera abundance.
Species structure in Zambian miombo woodland
Authors: Chidumayo E. N.
Published: July 2009

Miombo woodland in Zambia is divided into wetter and drier types by the 1100 mm mean rainfall isohyet. In the present study two wetter (Northern, Northwestern) and three drier (Central, Eastern, Western) miombo subtypes were recognized.

A survey of the woody flora of 94 old-growth and 58 coppice stands in the five miombo subtypes revealed some significant differences in species diversity among them. The floristic differentiantion of miombo subtypes was best achieved by the use of the Shannon species diversity index (H′) and species density (number of species 0.1 ha−1 or 0.4 ha−1). H′ in miombo decreased from 2.247 in Northwestern to 2.136 in Northern, 2.052 in Eastern, 1.918 in Central and 1.824 in Western subtypes. Although species density was not significantly different between wetter miombo subtypes, this decreased in a similar fashion from 18.78 0.1 ha−1 in Northwestern to 18.30 in Northern, 16.65 in Eastern, 14.79 in Central and 12.29 in Western subtypes. The low species diversity in Western drier miombo was attributed to the combined effects of low soil fertility and rainfall.

Although the mean number of species per 0.1 ha plot was higher in coppice samples, species richness (d) and index of diversity (H′) were lower than in old-growth samples. These results indicate lower species diversity in regenerating miombo. The dynamic aspects of species structure should therefore be considered in the future conservation of biological diversity in miombo woodland.
The seed bank ofEupatorium odoratumalong a successional gradient in a tropical rain forest in Ghana
Authors: Epp Gary A.
Published: July 2009

The germinable seed bank of the colonizing weedEupatorium odoratumwas studied at the University of Ghana's Agricultural Research Station, near Kade. Five sites representing different successional stages were selected: a closed-canopy forest; intermittent-canopy forest; secondary forest; agricultural land; and a burnt forest. Twenty-five soil samples (each 500 cm3; 10×10×5 cm) were taken at random in each site, to be used for germination experiments. The secondary forest site had significantly more seeds ofEupatorium odoratum(8428 seeds per m2) than any of the other four sites. In this siteEupatorium odoratumconstituted 81% of the total seed bank and had significantly more rapid germination of seeds than any other species. The results indicate that the existence of a soil seed bank may depend on: (1) time allowed for seed accumulation; (2) habitat accessibility to dispersing seeds; (3) the type of disturbance that occurs in an area; (4) dispersal capabilities of colonizing species; and (5) the history of the species′ distribution in the area.
Survival, development and predatory effects of mosquito larvae in Venezuelan phytotelmata
Authors: Lounibos L. P. , Frank J. H. , Machado-Allison C. E. , Ocanto P. , Navarro J. C.
Published: July 2009

To assess the influence of microhabitat and season on predator growth and survival and prey community structure, first instars of native Toxorhynchites haemorrhoidalis, a predatory mosquito, were released into Heliconia bracts, bamboo internodes, and the axils of two species of Aechmea bromeliads during wet and dry seasons in a lowland rain forest in eastern Venezuela. Experimental and control microhabitats were compared by complete censusing of macroscopic invertebrates 10 and 20 days after releases.

Survival of T. haemorrhoidalis differed significantly among habitats and was reduced by desiccation in dry-season bamboos and in Aechmea nudicaulis and by the presence of a predatory damselfly (Odonata: Zygoptera) in bromeliads. Developmental rate differed among habitats in the wet but not in the dry season; rapid wet-season maturation was associated with increased prey abundance in Heliconia.

Larvae of T. haemorrhoidalis consumed particular taxa and size categories of dipterous prey. Predation significantly reduced the abundance and skewed size-class distributions of Culicidae, Ceratopogonidae, Psychodidae, and pooled samples of Thaumaleidae plus Chironomidae. In bamboos, instar distributions of other mosquitoes were skewed in the presence of T. haemorrhoidalis even though a significant reduction in mosquito abundance was not detected. A decrease in species richness of aquatic Diptera was associated with intense predation by Toxorhynchites in Heliconia and A. nudicaulis.

Toxorhynchites theobaldi was recognized as the naturally occurring predator in local bamboos, and released larvae caused significant reductions in abundance or size-class frequency shifts among three families of Diptera. Niche segregation between these sympatric Toxorhynchites is maintained by oviposition preferences: the larger species, T. theobaldi, oviposits in bamboos and the smaller T. haemorrhoidalis occurs in plant bracts and axils.
Stemonoporus(Dipterocarpaceae)-dominated montane forests in the Adam's Peak Wilderness, Sri Lanka
Authors: Greller A. M. , Gunatilleke I. A. U. N. , Jayasuriya A. H. M. , Gunatilleke C. V. S. , Balasubramaniam S. , Dassanayake M. D.
Published: July 2009

StemonoporusThw. (Dipterocarpaceae), a genus endemic to Sri Lanka, contains as many as 26 species, all but one confined to the perhumid forests of the island. Several species reach 1800 m, the highest altitude recorded for any dipterocarp species in Sri Lanka. We report the first quantitative data onStemonoporus-domirated stands in the montane zone (1500–1700 m).Stemonoporus cordifoliusand 5.rigidusshow clear single-species dominance of their respective stands.Stemonoporus gardneriis a co-dominant withPalaquium rubiginosumin its two stands. AllStemonoporusspecies appear to have a unique geographical and ecological range and no twoStemonoporusspecies co-exist in our stands.
Forest tree growth and dynamics at La Selva, Costa Rica (1969-1982)
Authors: Lieberman Diana , Lieberman Milton
Published: July 2009

Permanent plots totalling 12.4 hectares were established in 1969 in primary tropical wet forest at La Selva Biological Station, Costa Rica; all stems ≥10 cm diameter at breast height were tagged and measured. In 1982, the plots were again censused, and all live trees re-measured. Mortality over 13 years was 23.2%, or 2.03% per year based on a logarithmic mortality model. This suggests a stand half-life of around 34 years. Mortality was independent of size class in trees ≥10 cm diameter. Recruitment was equal to mortality. Tree growth curves and age-size relationships for 44 species were projected from 13-year diameter increments using a growth simulation procedure. Understorey trees grow slowly and consistently, and have short life spans; subcanopy trees also grow slowly, but live longer; shade-tolerant canopy trees show variable and often rapid growth and are long-lived; and shade-intolerant canopy trees grow rapidly, show little variation, and have short life spans. The longest imputed life span in our sample was around 440 years (years from 10 cm diameter to the maximum diameter); the shortest life span was around 50 years.