bluuebunny/crossref_metadata_2025 huggingface dataset:
Focal Cryoablation of Prostate: A Review
Authors: Bahn Duke K. , Silverman Paul D.
Published: April 2008

Current treatment options for men with early localized prostate cancer are either some form of radical therapy or active surveillance. Radical therapy is usually associated with significant adverse effects that might jeopardize a man's quality of life. Some observers believe that PSA screening has resulted in the over diagnosis and over treatment of prostate cancer. Many men are being diagnosed with an early stage, small volume, unifocal or unilateral prostate cancer but are reluctant to accept watchful waiting or active surveillance. Focal cryoablation is the less than complete ablation of the gland with ice. Based on review of the limited amount of material available in the current literature, focal cryoablation can provide acceptable cancer control while preserving sexual potency and urinary continence. Focal cryoablation may fill a void in the therapeutic options available to patients with unifocal or unilateral prostate cancer who have a strong desire to maintain their quality of life.
Vasoactive Hormones and the Diabetic Kidney
Authors: Maric Christine
Published: April 2008

Diabetic nephropathy is the single most common cause of end-stage renal disease (ESRD) and accounts for significant morbidity and mortality. While the incidence of ESRD increased dramatically in the 1980s and 1990s, the U.S. Renal Data System (USRDS) 2005 Annual Data Report shows that 338 out of every million Americans had kidney failure in 2003, down slightly from 340 per million in 2002. This report shows that the numbers of people developing ESRD have stabilized despite the persistent increase in the number of people diagnosed with type 2 diabetes mellitus (T2DM). These data attest to both the efficacy of the currently available therapeutic regimens for the treatment of ESRD as well as better overall patient care. Unfortunately, these encouraging statistics do not apply to all patients. According to the USRDS report, the most marked ESRD decrease was seen in young Caucasian men (<40 years of age), while in other patient groups, particularly African Americans, ESRD has not changed much at all. These observations suggest that more in-depth studies, addressing specific issues, such as race, are needed to understand the disease process fully in order to create novel therapeutic strategies to eradicate the disease completely in all patient populations.

The most commonly used therapeutic treatments for diabetic nephropathy are angiotensin-converting enzyme (ACE) inhibitors and angiotensin II (Ang II) receptor blockers (ARBs), implicating the importance of the renin-angiotensin-aldosterone system (RAAS) in the pathophysiology of diabetic nephropathy. The RAAS is not the only vasoactive hormonal system that is involved in the disease process. Over the past decade, studies have suggested that other vasoactive hormones, including endothelin, urotensin II, and the kallikrein-kinin system (KKS), are instrumental in mediating structural and functional alterations in the renal vasculature and parenchyma, leading to the development and progression of diabetic nephropathy. This review will summarize our current understanding of the contribution of vasoactive hormones in the pathophysiology of diabetic nephropathy with specific emphasis on the RAAS, especially the more recently identified components of this hormonal pathway.
Treatment of Highland Frogs from the Two-Legged Stage with Homeopathically Prepared Thyroxin (10-11–10-21)
Authors: Lingg Gerhard , Endler P. Christian , Frass Michael , Lothaller Harald
Published: April 2008

The influence of moderately diluted, agitated, i.e., homeopathically prepared, thyroxin solutions (10-11–10-12, final concentration in the basin water 0.6 × 10-15− 0.6 × 10-25parts by weight after the first application) on metamorphosis in highlandRana temporariafrom the two-legged stage was studied. In accordance with the homeopathic idea of effects of specially prepared dilutions being inverse to those of their mother substances, animals were treated either with thyroxin 10-11–10-21or analogously prepared blank solution (water). Development was monitored by documenting the number of animals that had entered the four-legged stage. It has been found that animals treated with the thyroxin solutions metamorphosed more slowly than the control animals, i.e., the effect of the homeopathically prepared thyroxin was opposed to the usual effect of molecular thyroxin. The number of test animals that reached the four-legged stage at defined points in time was smaller (2–13.5%) in the group treated with homeopathically prepared thyroxin at the points in time, compared to control. The results in this study sustain the previous multiresearcher findings that show that diluted homeopathically prepared thyroxin is able to slow down metamorphosis ofR. temporaria.
Static T2w MRU in Noncalcular Urinary Obstruction: Comparison of Its Two Techniques
Authors: Abou El-Ghar Mohamed , Shokeir Ahmed , Rafaie Huda , El-Diasty Tarek
Published: April 2008

The purpose of this study was to compare the diagnostic accuracy of T2-weighted (T2w) MR urography (MRU) techniques — the standard MRU using fast spin echo (FSE) and postprocessing maximum intensity projection (MIP) and the single-shot MRU — in the diagnosis of ureteric obstruction in patients with noncalcular urinary obstruction. The study included 150 patients admitted to our center between January 2005 and December 2006. There were 203 renal units with noncalcular obstruction; 53 patients had bilateral obstruction. Patients with calcular obstruction were excluded. There were 85 males and 65 females with a mean age of 50 (range: 5–83) years. All patients were examined with static MRU using both single-shot (thick slab) and multisection MRU. Using single-shot MRU, we obtained images at the direct coronal and oblique coronal, as well as sagittal, planes for each renal unit. Postprocessing MIP for the standard coronal heavy T2 source images to obtain coronal and oblique images was done. Among the obstructed 203 units, the intrinsic causes were present in 157 units (151 were stricture and six were ureteric tumors), while the extrinsic causes were present in 46 units (35 bladder tumor, four ureterocele, five retroperitoneal fibrosis, one prostatic tumor, and one local pelvic recurrence after radical cystectomy for bladder cancer). The overall accuracy of single-shot MRU was 89% and was 93% for the multisection MRU in cases of intrinsic ureteric obstruction, while in cases of extrinsic obstruction, it was 20% for single-shot MRU and 96% for multisection MRU. T2w static MRU is a very useful technique in diagnosing noncalcular ureteric obstruction. Multisection MRU has a high diagnostic accuracy and reliability over that of the single-shot technique. The single-section technique is very rapid and useful in diagnosing ureteric stricture so it could be used as a localizer, while multisection images with postprocessing MIP is mandatory, especially in cases of suspected ureteric tumors or extraureteric causes.
Spontaneous Rupture of the Urinary Bladder 10 Years after Curative Radiotherapy
Authors: Labanaris Apostolos P. , Zugor Vahudin , Nützel Reinhold , Kühn Reinhard
Published: April 2008

It has been reported that the rate of clinically relevant side effects following curative radiotherapy for primary carcinoma is about 3% for urologic complications. Such complications include hematuria, fibrosis, and cystitis. An extremely rare, but dangerous, medical complication following curative radiotherapy that can also be noted is spontaneous bladder perforation. We present such a case of a 27-year-old patient with spontaneous bladder perforation, who was initially misdiagnosed because of its rarity as well as unspecific clinical and laboratory findings.
Enhancing the Urea-N Use Efficiency in Maize (Zea mays) Cultivation on Acid Soils Amended with Zeolite and TSP
Authors: Ahmed Osumanu H. , Hussin Aminuddin , Ahmad Husni M. H. , Rahim Anuar A. , Majid Nik Muhamad Abd.
Published: April 2008

Ammonia loss significantly reduces the urea-N use efficiency in crop production. Efforts to reduce this problem are mostly laboratory oriented. This paper reports the effects of urea amended with triple superphosphate (TSP) and zeolite (Clinoptilolite) on soil pH, nitrate, exchangeable ammonium, dry matter production, N uptake, fresh cob production, and urea-N uptake efficiency in maize (Zea mays) cultivation on an acid soil in actual field conditions. Urea-amended TSP and zeolite treatments and urea only (urea without additives) did not have long-term effect on soil pH and accumulation of soil exchangeable ammonium and nitrate. Treatments with higher amounts of TSP and zeolite significantly increased the dry matter (stem and leaf) production of Swan (test crop). All the treatments had no significant effect on urea-N concentration in the leaf and stem of the test crop. In terms of urea-N uptake in the leaf and stem tissues of Swan, only the treatment with the highest amount of TSP and zeolite significantly increased urea-N uptake in the leaf of the test crop. Irrespective of treatment, fresh cob production was statistically not different. However, all the treatments with additives improved urea-N uptake efficiency compared to urea without additives or amendment. This suggests that urea amended with TSP and zeolite has a potential of reducing ammonia loss from surface-applied urea.
Degradation of several hypomodified mature tRNA species in Saccharomyces cerevisiae is mediated by Met22 and the 5′–3′ exonucleases Rat1 and Xrn1
Authors: Chernyakov Irina , Whipple Joseph M. , Kotelawala Lakmal , Grayhack Elizabeth J. , Phizicky Eric M.
Published: April 2008

Mature tRNA is normally extensively modified and extremely stable. Recent evidence suggests that hypomodified mature tRNA in yeast can undergo a quality control check by a rapid tRNA decay (RTD) pathway, since mature tRNAVal(AAC) lacking 7-methylguanosine and 5-methylcytidine is rapidly degraded and deacylated at 37°C in a trm8-Δ trm4-Δ strain, resulting in temperature-sensitive growth. We show here that components of this RTD pathway include the 5′–3′ exonucleases Rat1 and Xrn1, and Met22, which likely acts indirectly through Rat1 and Xrn1. Since deletion of MET22 or mutation of RAT1 and XRN1 prevent both degradation and deacylation of mature tRNAVal(AAC) in a trm8-Δ trm4-Δ strain and result in healthy growth at 37°C, hypomodified tRNAVal(AAC) is at least partially functional and structurally intact under these conditions. The integrity of multiple mature tRNA species is subject to surveillance by the RTD pathway, since mutations in this pathway also prevent degradation of at least three other mature tRNAs lacking other combinations of modifications. The RTD pathway is the first to be implicated in the turnover of mature RNA species from the class of stable RNAs. These results and the results of others demonstrate that tRNA, like mRNA, is subject to multiple quality control steps.
Identification of active transcriptional regulatory modules by the functional assay of DNA from nucleosome-free regions
Authors: Yaragatti Mahesh , Basilico Claudio , Dailey Lisa
Published: April 2008

The identification of transcriptional regulatory modules within mammalian genomes is a prerequisite to understanding the mechanisms controlling regulated gene expression. While high-throughput microarray- and sequencing-based approaches have been used to map the genomic locations of sites of nuclease hypersensitivity or target DNA sequences bound by specific protein factors, the identification of regulatory elements using functional assays, which would provide important complementary data, has been relatively rare. Here we present a method that permits the functional identification of active transcriptional regulatory modules using a simple procedure for the isolation and analysis of DNA derived from nucleosome-free regions (NFRs), the 2% of the cellular genome that contains these elements. The more than 100 new active regulatory DNAs identified in this manner from F9 cells correspond to both promoter-proximal and distal elements, and display several features predicted for endogenous transcriptional regulators, including localization within DNase-accessible chromatin and CpG islands, and proximity to expressed genes. Furthermore, comparison with published ChIP-seq data of ES-cell chromatin shows that the functional elements we identified correspond with genomic regions enriched for H3K4me3, a histone modification associated with active transcriptional regulatory elements, and that the correspondence of H3K4me3 with our promoter-distal elements is largely ES-cell specific. The majority of the distal elements exhibit enhancer activity. Importantly, these functional DNA fragments are an average 149 bp in length, greatly facilitating future applications to identify transcription factor binding sites mediating their activity. Thus, this approach provides a tool for the high-resolution identification of the functional components of active promoters and enhancers.
Direct targets of the TRP63 transcription factor revealed by a combination of gene expression profiling and reverse engineering
Authors: Della Gatta Giusy , Bansal Mukesh , Ambesi-Impiombato Alberto , Antonini Dario , Missero Caterina , di Bernardo Diego
Published: April 2008

Genome-wide identification of bona-fide targets of transcription factors in mammalian cells is still a challenge. We present a novel integrated computational and experimental approach to identify direct targets of a transcription factor. This consists of measuring time-course (dynamic) gene expression profiles upon perturbation of the transcription factor under study, and in applying a novel “reverse-engineering” algorithm (TSNI) to rank genes according to their probability of being direct targets. Using primary keratinocytes as a model system, we identified novel transcriptional target genes of TRP63, a crucial regulator of skin development. TSNI-predicted TRP63 target genes were validated by Trp63 knockdown and by ChIP-chip to identify TRP63-bound regions in vivo. Our study revealed that short sampling times, in the order of minutes, are needed to capture the dynamics of gene expression in mammalian cells. We show that TRP63 transiently regulates a subset of its direct targets, thus highlighting the importance of considering temporal dynamics when identifying transcriptional targets. Using this approach, we uncovered a previously unsuspected transient regulation of the AP-1 complex by TRP63 through direct regulation of a subset of AP-1 components. The integrated experimental and computational approach described here is readily applicable to other transcription factors in mammalian systems and is complementary to genome-wide identification of transcription-factor binding sites.
Gene Expression and Metabolism in Tomato Fruit Surface Tissues
Authors: Mintz-Oron Shira , Mandel Tali , Rogachev Ilana , Feldberg Liron , Lotan Ofra , Yativ Merav , Wang Zhonghua , Jetter Reinhard , Venger Ilya , Adato Avital , Aharoni Asaph
Published: April 2008

The cuticle, covering the surface of all primary plant organs, plays important roles in plant development and protection against the biotic and abiotic environment. In contrast to vegetative organs, very little molecular information has been obtained regarding the surfaces of reproductive organs such as fleshy fruit. To broaden our knowledge related to fruit surface, comparative transcriptome and metabolome analyses were carried out on peel and flesh tissues during tomato (Solanum lycopersicum) fruit development. Out of 574 peel-associated transcripts, 17% were classified as putatively belonging to metabolic pathways generating cuticular components, such as wax, cutin, and phenylpropanoids. Orthologs of the Arabidopsis (Arabidopsis thaliana) SHINE2 and MIXTA-LIKE regulatory factors, activating cutin and wax biosynthesis and fruit epidermal cell differentiation, respectively, were also predominantly expressed in the peel. Ultra-performance liquid chromatography coupled to a quadrupole time-of-flight mass spectrometer and gas chromatography-mass spectrometry using a flame ionization detector identified 100 metabolites that are enriched in the peel tissue during development. These included flavonoids, glycoalkaloids, and amyrin-type pentacyclic triterpenoids as well as polar metabolites associated with cuticle and cell wall metabolism and protection against photooxidative stress. Combined results at both transcript and metabolite levels revealed that the formation of cuticular lipids precedes phenylpropanoid and flavonoid biosynthesis. Expression patterns of reporter genes driven by the upstream region of the wax-associated SlCER6 gene indicated progressive activity of this wax biosynthetic gene in both fruit exocarp and endocarp. Peel-associated genes identified in our study, together with comparative analysis of genes enriched in surface tissues of various other plant species, establish a springboard for future investigations of plant surface biology.
Tocotrienols, the Unsaturated Forms of Vitamin E, Can Function as Antioxidants and Lipid Protectors in Tobacco Leaves
Authors: Matringe Michel , Ksas Brigitte , Rey Pascal , Havaux Michel
Published: April 2008

Vitamin E is a generic term for a group of lipid-soluble antioxidant compounds, the tocopherols and tocotrienols. While tocotrienols are considered as important vitamin E components in humans, with functions in health and disease, the protective functions of tocotrienols have never been investigated in plants, contrary to tocopherols. We took advantage of the strong accumulation of tocotrienols in leaves of double transgenic tobacco (Nicotiana tabacum) plants that coexpressed the yeast (Saccharomyces cerevisiae) prephenate dehydrogenase gene (PDH) and the Arabidopsis (Arabidopsis thaliana) hydroxyphenylpyruvate dioxygenase gene (HPPD) to study the antioxidant function of those compounds in vivo. In young leaves of wild-type and transgenic tobacco plants, the majority of vitamin E was stored in thylakoid membranes, while plastoglobules contained mainly δ-tocopherol, a very minor component of vitamin E in tobacco. However, the vitamin E composition of plastoglobules was observed to change substantially during leaf aging, with α-tocopherol becoming the major form. Tocotrienol accumulation in young transgenic HPPD-PDH leaves occurred without any significant perturbation of photosynthetic electron transport. Tocotrienols noticeably reinforced the tolerance of HPPD-PDH leaves to high light stress at chilling temperature, with photosystem II photoinhibition and lipid peroxidation being maintained at low levels relative to wild-type leaves. Very young leaves of wild-type tobacco plants turned yellow during chilling stress, because of the strongly reduced levels of chlorophylls and carotenoids, and this phenomenon was attenuated in transgenic HPPD-PDH plants. While sugars accumulated similarly in young wild-type and HPPD-PDH leaves exposed to chilling stress in high light, a substantial decrease in tocotrienols was observed in the transgenic leaves only, suggesting vitamin E consumption during oxygen radical scavenging. Our results demonstrate that tocotrienols can function in vivo as efficient antioxidants protecting membrane lipids from peroxidation.
Gγ1 + Gγ2 ≠ Gβ: Heterotrimeric G Protein Gγ-Deficient Mutants Do Not Recapitulate All Phenotypes of Gβ-Deficient Mutants
Authors: Trusov Yuri , Zhang Wei , Assmann Sarah M. , Botella José Ramón
Published: April 2008

Heterotrimeric G proteins are signaling molecules ubiquitous among all eukaryotes. The Arabidopsis (Arabidopsis thaliana) genome contains one Gα (GPA1), one Gβ (AGB1), and two Gγ subunit (AGG1 and AGG2) genes. The Gβ requirement of a functional Gγ subunit for active signaling predicts that a mutant lacking both AGG1 and AGG2 proteins should phenotypically resemble mutants lacking AGB1 in all respects. We previously reported that Gβ- and Gγ-deficient mutants coincide during plant pathogen interaction, lateral root development, gravitropic response, and some aspects of seed germination. Here, we report a number of phenotypic discrepancies between Gβ- and Gγ-deficient mutants, including the double mutant lacking both Gγ subunits. While Gβ-deficient mutants are hypersensitive to abscisic acid inhibition of seed germination and are hyposensitive to abscisic acid inhibition of stomatal opening and guard cell inward K+ currents, none of the available Gγ-deficient mutants shows any deviation from the wild type in these responses, nor do they show the hypocotyl elongation and hook development defects that are characteristic of Gβ-deficient mutants. In addition, striking discrepancies were observed in the aerial organs of Gβ- versus Gγ-deficient mutants. In fact, none of the distinctive traits observed in Gβ-deficient mutants (such as reduced size of cotyledons, leaves, flowers, and siliques) is present in any of the Gγ single and double mutants. Despite the considerable amount of phenotypic overlap between Gβ- and Gγ-deficient mutants, confirming the tight relationship between Gβ and Gγ subunits in plants, considering the significant differences reported here, we hypothesize the existence of new and as yet unknown elements in the heterotrimeric G protein signaling complex.
The Wheat Mitogen-Activated Protein Kinases TaMPK3 and TaMPK6 Are Differentially Regulated at Multiple Levels during Compatible Disease Interactions withMycosphaerella graminicola
Authors: Rudd Jason J. , Keon John , Hammond-Kosack Kim E.
Published: April 2008

Many race- or isolate-specific disease resistance responses of plants toward pathogens (incompatible interactions) invoke hypersensitive response (HR)-like programmed cell death (PCD) and the coordinated activation of mitogen-activated protein kinases homologous with Arabidopsis (Arabidopsis thaliana) AtMPK6 and AtMPK3 (or tobacco [Nicotiana tabacum] SIPK and WIPK), respectively. Resistance of wheat (Triticum aestivum) leaves to the necrotrophic fungal pathogen Mycosphaerella graminicola can also operate at an isolate/cultivar-specific level. We confirm here that resistance is achieved without any sign of HR-like PCD during the incompatible interaction. Instead, PCD is strictly associated with the compatible interaction and is triggered during disease symptom expression. A strong transcriptional activation of TaMPK3, the wheat homolog of Arabidopsis AtMPK3, was observed immediately preceding PCD and symptom development in the compatible interaction. Generation and use of TaMPK3- and TaMPK6-specific antibodies on western blots and in coupled immunoprecipitation-protein kinase assays demonstrated that the TaMPK3 protein also accumulated, and was subsequently posttranslationally activated, during the compatible interaction in parallel to PCD. In contrast, no increase in expression, protein levels, or posttranslational activation of TaMPK6 was observed at any stage of either compatible or incompatible interactions. However, the protein levels of TaMPK6 became markedly reduced during the compatible interaction coincident with the onset of TaMPK3 protein accumulation. These data highlight the emerging similarity between the signaling pathways triggered in a host plant during successful infection by a necrotrophic fungal pathogen and the resistance responses normally effective against biotrophs.
A Pentapeptide Motif Related to a Pigment Binding Site in the Major Light-Harvesting Protein of Photosystem II, LHCII, Governs Substrate-Dependent Plastid Import of NADPH:Protochlorophyllide Oxidoreductase A
Authors: Reinbothe Christiane , Pollmann Stephan , Phetsarath-Faure Phetaphine , Quigley Françoise , Weisbeek Peter , Reinbothe Steffen
Published: April 2008

NADPH:protochlorophyllide (Pchlide) oxidoreductase (POR) A is the only known example thus far of a nucleus-encoded plastid protein that is imported to its final destination in a substrate-dependent, Pchlide-regulated manner. Previous work has shown that the cytosolic PORA precursor (pPORA) does not utilize the general import site but uses a distinct translocon designated the Pchlide-dependent translocon complex. Here we demonstrate that a pentapeptide motif, threonine-threonine-serine-proline-glycine (TTSPG) in pPORA's transit peptide (transA), is involved in Pchlide-dependent transport. Deletion of this motif from the COOH-terminal end of transA abolished both Pchlide binding and protein import. Incorporation of the TTSPG motif into normally non-Pchlide-responsive transit sequences conferred the pigment binding properties onto the engineered chimeric precursors but was insufficient to render protein import substrate dependent. An additional motif was identified in the NH2-terminal part of transA that was needed for binding of the precursor to the Pchlide-dependent translocon complex. Point mutations of the TTSPG motif identified glycine as the Pchlide binding site. By analogy to the major light-harvesting chlorophyll a/b binding protein of photosystem II, we propose that the peptidyl carbonyl oxygen of glycine may bind directly or via a water molecule to the central Mg atom of the pigment.
Plastid Transcriptomics and Translatomics of Tomato Fruit Development and Chloroplast-to-Chromoplast Differentiation: Chromoplast Gene Expression Largely Serves the Production of a Single Protein
Authors: Kahlau Sabine , Bock Ralph
Published: April 2008

Plastid genes are expressed at high levels in photosynthetically active chloroplasts but are generally believed to be drastically downregulated in nongreen plastids. The genome-wide changes in the expression patterns of plastid genes during the development of nongreen plastid types as well as the contributions of transcriptional versus translational regulation are largely unknown. We report here a systematic transcriptomics and translatomics analysis of the tomato (Solanum lycopersicum) plastid genome during fruit development and chloroplast-to-chromoplast conversion. At the level of RNA accumulation, most but not all plastid genes are strongly downregulated in fruits compared with leaves. By contrast, chloroplast-to-chromoplast differentiation during fruit ripening is surprisingly not accompanied by large changes in plastid RNA accumulation. However, most plastid genes are translationally downregulated during chromoplast development. Both transcriptional and translational downregulation are more pronounced for photosynthesis-related genes than for genes involved in gene expression, indicating that some low-level plastid gene expression must be sustained in chromoplasts. High-level expression during chromoplast development identifies accD, the only plastid-encoded gene involved in fatty acid biosynthesis, as the target gene for which gene expression activity in chromoplasts is maintained. In addition, we have determined the developmental patterns of plastid RNA polymerase activities, intron splicing, and RNA editing and report specific developmental changes in the splicing and editing patterns of plastid transcripts.
Analysis of theArabidopsisHistidine Kinase ATHK1 Reveals a Connection between Vegetative Osmotic Stress Sensing and Seed Maturation
Authors: Wohlbach Dana J. , Quirino Betania F. , Sussman Michael R.
Published: April 2008

To cope with water stress, plants must be able to effectively sense, respond to, and adapt to changes in water availability. The Arabidopsis thaliana plasma membrane His kinase ATHK1 has been suggested to act as an osmosensor that detects water stress and initiates downstream responses. Here, we provide direct genetic evidence that ATHK1 not only is involved in the water stress response during early vegetative stages of plant growth but also plays a unique role in the regulation of desiccation processes during seed formation. To more comprehensively identify genes involved in the downstream pathways affected by the ATHK1-mediated response to water stress, we created a large-scale summary of expression data, termed the AtMegaCluster. In the AtMegaCluster, hierarchical clustering techniques were used to compare whole-genome expression levels in athk1 mutants with the expression levels reported in publicly available data sets of Arabidopsis tissues grown under a wide variety of conditions. These experiments revealed that ATHK1 is cotranscriptionally regulated with several Arabidopsis response regulators, together with two proteins containing novel sequences. Since overexpression of ATHK1 results in increased water stress tolerance, our observations suggest a new top-down route to increasing drought resistance via receptor-mediated increases in sensing water status, rather than through genetically engineered changes in downstream transcription factors or specific osmolytes.
Reduced V-ATPase Activity in thetrans-Golgi Network Causes Oxylipin-Dependent Hypocotyl Growth Inhibition inArabidopsis
Authors: Brüx Angela , Liu Tzu-Yin , Krebs Melanie , Stierhof York-Dieter , Lohmann Jan U. , Miersch Otto , Wasternack Claus , Schumacher Karin
Published: April 2008

Regulated cell expansion allows plants to adapt their morphogenesis to prevailing environmental conditions. Cell expansion is driven by turgor pressure created by osmotic water uptake and is restricted by the extensibility of the cell wall, which in turn is regulated by the synthesis, incorporation, and cross-linking of new cell wall components. The vacuolar H+-ATPase (V-ATPase) could provide a way to coordinately regulate turgor pressure and cell wall synthesis, as it energizes the secondary active transport of solutes across the tonoplast and also has an important function in the trans-Golgi network (TGN), which affects synthesis and trafficking of cell wall components. We have previously shown that det3, a mutant with reduced V-ATPase activity, has a severe defect in cell expansion. However, it was not clear if this is caused by a defect in turgor pressure or in cell wall synthesis. Here, we show that inhibition of the tonoplast-localized V-ATPase subunit isoform VHA-a3 does not impair cell expansion. By contrast, inhibition of the TGN-localized isoform VHA-a1 is sufficient to restrict cell expansion. Furthermore, we provide evidence that the reduced hypocotyl cell expansion in det3 is conditional and due to active, hormone-mediated growth inhibition caused by a cell wall defect.
Combinatorial engineering to enhance thermostability of amylosucrase
Authors: Emond Stéphane , André Isabelle , Jaziri Kais , Potocki‐Véronèse Gabrielle , Mondon Philippe , Bouayadi Khalil , Kharrat Hakim , Monsan Pierre , Remaud‐Simeon Magali
Published: April 2008

Amylosucrase is a transglucosidase that catalyzes amylose‐like polymer synthesis from sucrose substrate. About 60,000 amylosucrase variants from two libraries generated by the MutaGen random mutagenesis method were submitted to an in vivo selection procedure leading to the isolation of more than 7000 active variants. These clones were then screened for increased thermostability using an automated screening process. This experiment yielded three improved variants (two double mutants and one single mutant) showing 3.5‐ to 10‐fold increased half‐lives at 50°C compared to the wild‐type enzyme. Structural analysis revealed that the main differences between wild‐type amylosucrase and the most improved variant (R20C/A451T) might reside in the reorganization of salt bridges involving the surface residue R20 and the introduction of a hydrogen‐bonding interaction between T451 of the B′ domain and D488 of flexible loop 8. This double mutant is the most thermostable amylosucrase known to date and the only one usable at 50°C. At this temperature, amylose synthesis by this variant using high sucrose concentration (600 mM) led to the production of amylose chains twice as long as those obtained by the wild‐type enzyme at 30°C.
THE BLACK RHINOCEROS (DICEROS BICORNIS L.)
Authors: Ritchie A. T. A.
Published: April 2008

Summary

The two African genera of rhinoceroses are briefly compared and an account given of the distribution of the black rhinoceros (Diceros bicornis L.). This species, which is adapted to a wide range of habitats, is now absent from or scarce in many parts of Africa where it was common only 50 or 100 years ago. It is described in detail with comments on the validity of the two subspecies D. b. bicornis and D. b. somaliensis Potocki.

Daily activity and home range of the black rhinoceroy are largely related to its water requirements. and it normally drinks once in 24 hours. In order to feed it may move 5–15 miles from the watering place along regular paths; feeding takes place in the early morning and evening and the remainder of the day is spent resting in shaue. A constant behaviour pattern during defaecation and urination is described.

A group or herd is usually composed of one, two or three individuals. Mating may take place at any time during the year. The disposition of individual animals is considered to be related to the degree to which they have been persecuted by man; in different areas, inhabited by hunting or pastoral tribes, a marked difference in behaviour is apparent. Instances have been recorded of black rhinoceroses being killed by elephants (Loxodonta africana Blumenbach) and by lions (Panther a leo Linnaeus).

An account is given of the structure of the horns and the way in which they are used. and of their commercial value. Poaching of the species in Kenya is carried out largely by means of poisoned arrows or leg snares.

Warning is given of the urgent need for strict measures to concerve the species. which will only survive in sanctuaries where its interests are paramount. Its decline is due not only to the impact of man but to its apparent inability to extend its range into areas where rhinos have not formerly existed. It is one of the species in most danger of extinction.

(Editorial note: this paper was written by the late A. T. A. Ritchie, Chief Game Warden of Kenya from 1923 to 1948, some time before his death in 1962. Ritchie was a fine observer and naturalist whose special interest was the black rhinoceros, and the editorial committee consider it particularly suitable that this record of his observations should be published in the first number of the East African Wildlife Journal to which he would undoubtedly have given wholehearted support. It should be pointed out that certain facts in the paper are now outdated. Some authorities consider the white rhino to be a species of Diceros, and poaching and other effects of man's presence are now a major factor in the decline of the black rhinoceros. Even with the present degree of control poaching is rife, and if this control is materially decreased the rhinoceros will undoubtedly rapidly disappear from many areas.)
OBSERVATIONS ON THE GREATER KUDU TRAGELAPHUS STREPSICEROS PALLAS FROM A TSETSE CONTROL HUNTING SCHEME IN NORTHERN RHODESIA
Authors: Wilson Vivian J.
Published: April 2008

Material from kudu shot on tsetse control was studied for information on breeding and feeding habits. A number of animals was measured and weighed, illustrating that males were bigger than females.

Field observations and stomach contents showed that the species is mainly a browser eating a wide variety of plants.

A marked peak of calving was observed and this coincided with the tall grass season (January‐April), when the newly‐born young are apparently hidden. Kudu in the area studied may be solitary but are generally associated in small groups of about four, although as many as eleven have been seen together in the study area.
A SURVEY OF PAST AND PRESENT WILDLIFE RESEARCH IN EAST AFRICA*
Authors: Talbot Lee M.
Published: April 2008

The survey involved visits throughout East Africa to contact those concerned with wildlife research, as well as a review of the available literature. This paper presents the results of the survey.

Wildlife research in East Africa is not a unified field and pertinent data come from a variety of disciplines. Broadly speaking there are four major types of research involving wildlife that have been or are being carried out in East Africa:

1. Observations on natural history;

2. Taxonomic and distributional studies;

3. Research in other fields which happens to involve wildlife;

4. Systematic research focused on wildlife itself.

To facilitate the use of this report the information on research projects and research workers has been presented under a series of subject headings, as follows: background and early references (p. 62), techniques (p. 63), taxonomy and nomenclature (p. 66), distribution and habitat preferences (p. 67), studies on individual species of large herbivores (p. 67), studies of predators (p. 69), ecological studies, including those of groups of associated animals (p. 69), population dynamics (p. 70), carrying capacity and biomass (p. 71), movements (p. 71), nutrition (p. 72), anatomy and physiology (p. 73), diseases and parasites (p. 73), small mammals (p. 75), birds (p. 75), reptiles (p. 75), primates (p. 76), vermin (p. 76), co‐ordination and publication of research (p. 76). Some studies of course appear under more than one heading. Within each heading the research is presented in chronological order. References, where available, are cited and the location of reports, files and sources of further information on each subject is noted.
THE USE OF GAME TRAILS AS A POSSIBLE MEASURE OF HABITAT UTILISATION BY LARGER MAMMALS
Authors: Agnew A.D.Q.
Published: April 2008

Percentage cover of game trails is discussed as a possible measure of total habitat utilisation by larger mammals and a technique for its measurement is described. Game trail cover in Tsavo National Park (East) at Voi has been analysed in two areas, woodland and grassland. Of these the woodland had the higher trail cover (10.69%) and grassland the lower (7.57%). The interpretation of these results is discussed.
THE FEEDING HABITS OF THE YELLOW‐NECKED SPURFOWL (PTERNISTIS LEUCOSCEPU8) IN NORTHERN TANZANIA
Authors: Stronach B.
Published: April 2008

In late 1984 and throughout 1965 the feeding habits of Pternistis leucoscepus were studied in the north of Tanzania and in the Tsavo West National Park in Kenya.

The main food of this bird was found to be the corms of the sedge Cyperus rotundus. Grass and legume seeds and insects formed a small proportion of the diet. P. leucoscepus is not dependent on free water and can occupy waterless country.

The species' main habitat is the edge of flood plains with abundant C. rotundus sedge, bounded by shrub and small tree cover.

In the two main study areas, Ngase‐rai and Tarangire, the difference in the general density of the habitats is reflected in the occurrence of P. leucoscepus and Francolinus sephaena together in the former area, and of P. leucoscepus, P. cranchii, F. sephaena and F. hildebrandti in the latter. The sympat‐ric occurrence of these related game birds and the apparent similarity of the two spurfowls' feeding habits presents a fascinating ecological problem for further study.
THE EFFECTS OF TSETSE CONTROL OPERATIONS ON COMMON DUIKER IN EASTERN ZAMBIA
Authors: Wilson V. J. , Roth H. H.
Published: April 2008

The effects of intensive Tsetse Control hunting operations on a duiker population (Sylvicapra grimmia) were investigated in a 200 sq. mile area in Eastern Zambia. Two years of hunting were insufficient to reduce this population so significantly that a marked shift of its age composition towards the juvenile age classes resulted. There were, however, indications of beginning accelerated population growth through increased breeding and inclusion of more juveniles in the reproduction process, as a first response to the hunting pressure. Although general availability of duiker did not diminish, they became increasingly difficult to shoot because of behavioural adaptation and changing periods of feeding activity. Neither hunting nor various other human disturbances provoked emigration from the area or a change of the seasonal pattern of localised movement.

The studied hunting operation failed to remove more than the annual increment to the duiker population and in respect of this species was thus ineffective as a means of Tsetse Control.

Implications of the results of this study for the management of duiker for sustained meat production are discussed.
NOTES ON SOME ANTS IN NORTHERN SOMALIA
Authors: Glover P. E.
Published: April 2008

The paper describes observations made over a period of two years on the feeding habits, general ecology and distribution of five species of ants (harvester‐, stink‐, soldier‐, tree‐, and sugar‐ants) in Northern Somalia, p‐incipally in the plains and bushland of the Haud.

Harvester and stink ants are discussed in some detail, and some dimensions of excavated nests and runways are given. The occurrence of associated insects is noted and the ecological roles of seed‐eating and predatory ants (particularly in relation to termites) are discussed.

There are notes on the climate and topography of the region, and a glossary of vernacular names is appended.
NAIROBI NATIONAL PARK GAME CENSUS, 1966
Authors: Foster J. B. , Kearney D.
Published: April 2008

1. The monthly game counts of Nairobi National Park in 1966 are compared with those of 1961 to 1983 inclusive. It appears that the mean an‐nual population of wild ungulates has remained constant at about 4000 animais after a severe decline during the drought of 1961.

2. Wildebeest have continued to decline since the drought and there is no evidence of the former migration to the Athi‐Kapiti plains. Reasons for these phenomena are proposed.

3. Kongoni have continued to in‐crease since their decline in 1961 and little migration to the plains could be detected in 1966.

4. The mean yearly population of zebra has remained constant since their decline in 1961. At present this is the only species to migrate in large num‐bers to and from the plains with the onset and cessation of the rains.

5. Other ungulates were less affected by the drought and their numbers in 1966 appear to have changed relatively little since the beginning of 1961.

6. Females predomInate in the adult populations of all the common plains ungulates.

7. In 1966 lions killed wildebeest at a rate four times greater than would be expected from the percentage of wildebeest in the population. Reasons for this are suggested. As the wildebeest have declined in numbers, the lion have included higher percentages of zebra, warthog, kongoni and eland in their diets.
DENTITION AND AGEING OF THE HIPPOPOTAMUS
Authors: Laws R. M.
Published: April 2008

I. Summary

The present paper is based on the examination of lower jaws from some 3000 individuals of Hippopotamus amphibius L. which were collected in the course of cropping operations in the Queen Elizabeth Park, Uganda between 1961 and 1966.

It extends an earlier study by W. M. Longhurst, who described 20 relative age groups based on tooth replacement and wear. The age groups, slightly modified, are described and illustrated here and should serve as a useful field guide.

Mean chronological ages from 0–43 years have been allocated to the groups.

Checks which confirm the validity of the ages allotted are presented and discussed. These include correlation with the mandibular age group of six known‐age animals; findings on the age‐related incidence of rinderpest‐neutralising antibodies; the orderly progress of fusion of the mandibular symphysis and rate of loss of the first premolar. Growth layers present in the teeth are discussed.

The growth of the eye lens is also described. After an initial phase of rapid growth the lens continues to grow throughout life and follows a rectilinear pattern from an estimated age of eight years onwards. This is expected from the findings of similar studies on other species for which known‐age specimens are available. Variability of lens dry weight at age is relatively small and indicates that the estimated ages are reasonably precise.

Growth of the mandible is analysed and is not inconsistent with the ages allotted. A marked sex difference in mandible weight at age allows the sex of found jaws to be determined at ages above eight years.

The growth of the teeth is described. Both canines and incisors show well‐marked sex differences in growth rate and size. The post‐canine teeth do not show sex differences. Cycles of growth, wear and resorption of these teeth are discussed and it is concluded that mechanical senescence of the teeth is a major factor in mortality at ages above 30 years.

Growth in body length is briefly discussed and provides further confirmation of the validity and precision of the age criteria. Growth equations are presented.

Finally a survivorship curve derived from the ageing of 207 jaws assumed to represent natural deaths is presented. Population models are constructed from the survivorship curves by calculation of estimated natality rates (obtained by applying data on age at first breeding and annual pregnancy rate to the survivorship data) and life tables are constructed. The shape of the survivorship curve and the percentage recruitment agree with expectation and provide further evidence of the consistency of the age criteria.
OBSERVATIONS ON THE CHANGING VEGETATION OF TSAVO NATIONAL PARK (EAST)
Authors: Agnew A. D. Q.
Published: April 2008

An analysis of woody vegetation in Tsavo National Park (East) by extensive variable‐plot sampling indicates that the vegetation had been differentially destroyed up to 1966, but that by 1967 considerable local shrub regeneration had taken place. This may indicate that Commiphora woodland will become re‐established over much of the park.
A QUANTITATIVE STUDY OF THE DAILY ACTIVITY OF THE UGANDA DEFASSA WATERBUCK
Authors: Spinage C. A.
Published: April 2008

Waterbuck activity was recorded at four‐minute intervals for continuous periods of 12 hours on two or three consecutive days, and for single nocturnal periods. Feeding patterns of the male and female were similar and during the day there was no hour during which some feeding did not take place. Only male activity was recorded at night. This showed more intensive feeding but with periods of no feeding just after dark and just before dawn. The use of a four‐minute recording interval was found to work well in practice.
HUNTING BEHAVIOUR OF THE CHEETAH IN THE SERENGETI NATIONAL PARK, TANZANIA
Authors: Schaller George B.
Published: April 2008

Eighty‐nine per cent, of 136 cheetah kills in the Serengeti National Park consisted of Thomson's gazelles, the most abundant and readily available species in the size category (60 kg or less) preferred by the cheetah. Fifty‐four per cent, of the Thomson's gazelle kills were subadult; among the adults all age classes were represented. One female cheetah captured 24 Thomson's gazelles in 26 days, a killing rate of 10 kg/day. The actual food intake of this female was about 4 kg/day. The hunting success of cheetah pursuing large subadult and adult Thomson's gazelles was about 50 per cent.

The hunting methods–including the various means of approaching prey–are described as are the typical ways of killing and feeding. Twelve per cent, of the cheetah kills were appropriated by lions and hyaenas.
OBSERVATIONS ON THE FOOD HABITS OF TAME WARTHOG AND ANTELOPE IN UGANDA
Authors: Field C. R.
Published: April 2008

Monthly observations were made of the food habits of tame warthog, reedbuck and kob over a period of a year. Measurements were taken of the shoulder height and size of mouth of the animals at different stages of their growth.

Whilst a few species of grass were regularly preferred, the majority showed fluctuations in their preference. Some consistent seasonal differences were apparent. Most herbs were avoided.

Large differences in food habits occurred between warthog and antelope; however, there was some overlap during the rains when food was abundant and at the height of the dry season when it was scarce. Some differences were apparent between kob and reedbuck and between individual warthog and reedbuck. Intraspecific differences, however, were less noticeable than interspecific differences.

The height of the animal and the size of its mouth were important in determining the portion of the sward available for food and the degree of selection possible within the available food supply.