bluuebunny/crossref_metadata_2025 huggingface dataset:
Major Cdk5‐dependent phosphorylation sites of amphiphysin 1 are implicated in the regulation of the membrane binding and endocytosis
Authors: Liang Shuang , Wei Fan‐Yan , Wu Yu‐Mei , Tanabe Kenji , Abe Tadashi , Oda Yoshiya , Yoshida Yumi , Yamada Hiroshi , Matsui Hideki , Tomizawa Kazuhito , Takei Kohji
Published: April 2007

Amphiphysin 1 (amph 1) is an endocytic protein enriched in the nerve terminals that functions in the clathrin‐mediated endocytosis. It acts as membrane curvature sensor, a linker of clathrin coat proteins, and an enhancer of dynamin Guanosine Triphosphatase (GTPase) activity. Amph 1 undergoes phosphorylation by cyclin‐dependent kinase 5 (Cdk5), at five phosphorylation sites, serine 262, 272, 276, 285, and threonine 310, as determined by mass spectrometry (MS). We show here that Cdk5‐dependent phosphorylation of amph 1 is enhanced in the presence of lipid membranes. Analysis by tandem liquid chromatograph MS revealed that the phosphorylation occurs at two phosphorylation sites. The phosphorylation was markedly decreased by mutation either Ser276 or Ser285 of amph 1 to alanine (S276A and S285A). Furthermore, mutation of both sites (S276, 285A) completely eliminated the phosphorylation. Functional studies indicated that binding of amph 1 to lipid membrane was attenuated by Cdk5‐dependent phosphorylation of wild type amph 1, but not of the S276, 285A form. Interestingly, endocytosis was increased in rat pheochromocytoma cells expressing amph 1 S276, 285A in comparison with wild type. These results suggest that Ser276 and Ser285 are regulatory Cdk5 phosphorylation sites of amph 1 in the lipid‐bound state. Phosphorylation at these sites alters binding of amph 1 to lipid membranes, and may be an important regulatory aspect in the regulation of synaptic vesicle endocytosis.
Rapid regulation of dopamine transporters by tyrosine kinases in rat neuronal preparations
Authors: Hoover B. R. , Everett C. V. , Sorkin A. , Zahniser N. R.
Published: April 2007

Termination of dopamine neurotransmission is primarily controlled by the plasma membrane‐localized dopamine transporter. In this study, we investigated how this transporter is regulated by tyrosine kinases in neuronal preparations. In rat dorsal striatal synaptosomes, inhibition of tyrosine kinases by genistein or tyrphostin 23 resulted in a rapid (5–15 min), concentration‐dependent decrease in [3H]dopamine uptake because of a reduction in maximal [3H]dopamine uptake velocity and dopamine transporter cell surface expression. The reduced transporter activity was associated with a decrease in phosphorylated p44/p42 mitogen‐activated protein kinases. In primary rat mesencephalic neuronal cultures, the tyrosine kinase inhibitors similarly reduced [3H]dopamine uptake. When cultures were serum‐deprived, acute activation of tyrosine kinase‐coupled TrkB receptors by 100 ng/mL brain‐derived neurotrophic factor significantly increased [3H]dopamine uptake; the effects were complex with increased maximal velocity but reduced affinity. The facilitatory effect of brain‐derived neurotrophic factor on dopamine transporter activity depended on both the mitogen‐activated protein kinase and phosphatidylinositol 3‐kinase pathways. Taken together, our results suggest that striatal dopamine transporter function and cell surface expression is constitutively up‐regulated by tyrosine kinase activation and that brain‐derived neurotrophic factor can mediate this type of rapid regulation.
Loss of hippocampal neuronal nitric oxide synthase contributes to the stress‐related deficit in learning and memory
Authors: Palumbo María Laura , Fosser Nicolás Sebastián , Rios Hugo , Zubilete María Aurelia Zorrilla , Guelman Laura Ruth , Cremaschi Graciela Alicia , Genaro Ana María
Published: April 2007

Nitric oxide (NO) has been involved in many pathophysiological brain processes. However, the exact role of NO in the cognitive deficit associated to chronic stress exposure has not been elucidated. In this study, we investigated the participation of hippocampal NO production and their regulation by protein kinase C (PKC) in the memory impairment induced in mice subjected to chronic mild stress model (CMS). CMS mice showed a poor learning performance in both open field and passive avoidance inhibitory task respect to control mice. Histological studies showed a morphological alteration in the hippocampus of CMS mice. On the other hand, chronic stress induced a diminished NO production by neuronal nitric oxide synthase (nNOS) correlated with an increment in gamma and zeta PKC isoenzymes. Partial restoration of nNOS activity was obtained after PKC activity blockade. NO production by inducible nictric oxide synthase isoform was not detected. The magnitude of oxidative stress, evaluated by reactive oxygen species production, after excitotoxic levels of NMDA was increased in hippocampus of CMS mice. Moreover, ROS formation was higher in the presence of nNOS inhibitor in both control and CMS mice. Finally, treatment of mice with nNOS inhibitors results in behavioural alterations similar to those observed in CMS animals. These findings suggest a novel role for nNOS showing protective activity against insults that trigger tissue toxicity leading to memory impairments.
Establishment and characterization of a novel imatinib‐sensitive chronic myeloid leukemia cell line MYL, and an imatinib‐resistant subline MYL‐R showing overexpression of Lyn
Authors: Ito Takuo , Tanaka Hideo , Kimura Akiro
Published: April 2007

In chronic myeloid leukemia (CML), resistance to imatinib is diverse. In addition to BCR‐ABL‐dependent mechanisms, BCR‐ABL‐independent mechanisms have been proposed. Here we established and characterized novel CML cell lines, an imatinib‐sensitive cell line, MYL, and an imatinib‐resistant subline, MYL‐R. Treatment with imatinib inhibited phosphorylation of BCR‐ABL and CrkL in both MYL and MYL‐R, even though imatinib‐induced apoptosis was preferentially observed in MYL than MYL‐R, indicating that the resistance is based on a BCR‐ABL‐independent mechanism. MYL‐R showed elevated expressions of Lyn mRNA, Lyn protein, phosphorylated Lyn, and phosphorylated STAT5. Silencing of Lyn by short‐interfering RNA (siRNA) in MYL‐R, but not in MYL, induced significant growth‐inhibition, increased caspase‐3 activity, and induced partial recovery from imatinib‐resistance. Expression of Bcl‐2, previously reported to be associated with Lyn‐mediated resistance, was not elevated in MYL‐R. Expression of Bim, which plays an important role in imatinib‐induced cell‐killing, was not suppressed in MYL‐R. These results imply that diverse mechanisms of resistance exist among cell types. Treatment of MYL‐R cells with various reagents known to have anti‐leukemic activity revealed that zoledronic acid and the farnesyl transferase inhibitor (SCH 66336) showed strong synergism with imatinib; interferon α, PP2, CGP76030, and FK228 (depsipeptide) showed synergism; whereas soluble TRAIL and As2O3 showed additivity or antagonism, and 17‐AAG and radicicol showed antagonism. Treatment with either PP2 or zoledronic acid induced greater growth‐reduction in MYL‐R than MYL. Taken together, Lyn may play an important role in imatinib‐resistance in MYL‐R. Some novel reagents, including siRNA targeting Lyn, may have good potential to overcome this resistance.
Psychosis as presenting symptom in adult-onset Hallervorden-Spatz syndrome
Authors: Panas Marios , Spengos Konstantinos , Koutsis Georgios , Tsivgoulis Georgios , Sfagos Konstantinos , Kalfakis Nikolaos , Vassilopoulos Dimitris
Published: April 2007

Background:

Hallervorden-Spatz syndrome is characterized by pyramidal and extrapyramidal signs, and dysarthria and dementia. Psychiatric symptomatology can emerge in the course of the disorder. Mutations in the pantothenate kinase 2 gene have been found in many cases. We report a case with psychosis as sole presenting symptom.

Case:

A 41-year-old man presented with change in behavior and paranoid delusional ideation. Six months later, spasticity, extrapyramidal rigidity and dysarthria were added to the picture. Eventually, the patient became mute and wheel-chair bound. The brain magnetic resonance imaging (MRI) was consistent with iron depositions in the globus pallidus and substantia nigra.

Conclusions:

In this case, the combination of clinical and MRI findings was consistent with Hallervorden-Spatz syndrome. The combination of psychiatric and MRI findings should lead to further neurological investigation.
Obsessive compulsive disorder in adults with rheumatic heart disease
Authors: Ashfaq-U-Rahaman  , Janardhan Reddy Y. C , Prabhavathi  , Pal Pramod Kumar
Published: April 2007

Objective:

There are considerable data on the possible association between streptococcal infection and obsessive compulsive disorder (OCD), particularly the relation between Sydenham’s chorea (SC) and OCD. However, neuropsychiatric sequelae related to streptococcal infection are mainly reported in children. In this preliminary study, we examined prevalence of OCD in a group of adult subjects with established rheumatic heart disease (RHD). We hypothesized that the rate of OCD would be higher than the known general population rates.

Method:

One hundred adult subjects with RHD were evaluated for OCD and other comorbid psychiatric disorders using well-known psychiatric assessment tools. A qualified psychiatrist conducted the assessments. The diagnoses were made according to DSM-IV criteria.

Results:

The rate of clinical OCD and subclinical OCD was 10% and 3%, respectively (n= 13), a rate much higher than the 1–3% rate reported in general population. Of the 13 subjects, only three had a history of SC (23%).

Conclusions:

OCD could be a long-term sequel in adults with a history of rheumatic fever in childhood, even in the absence of frank chorea. The findings call for systematic research in this little explored area.
Formation of Bone around Titanium Implants Placed into Zero Wall Defects: Pilot Project Using Reinforced e‐PTFE Membrane and Autogenous Bone Grafts
Authors: Akimoto Ken , Becker William , Donath Karl , Becker Burton E. , Sanchez Raquel
Published: April 2007

Background: Guided bone regeneration (GBR) frequently is used to augment implants with various types of bone defects. The defects often are grafted with different materials, yet there is insufficient evidence that these materials enhance bone‐to‐implant contacts.

Purpose: The purpose of this pilot project was to test the principle of GBR to promote bone formation adjacent to commercially pure titanium implants placed within zero‐wall defects. Histologic and histomorphometric measurements were used to evaluate new bone formation.

Materials and Methods: Under appropriate anesthesia, deep, wide defects were created within the mandibles of two large dogs. Buccolingual bone was removed to the depth of the defects leaving only the mesial and distal walls. Of the eight implants placed, three were augmented with titanium‐reinforced expanded polytetrafluoroethylene (e‐PTFE) barriers and autogenous bone chips. Three sites were augmented with barrier membranes only, and two sites were not augmented or grafted and served as controls. Seven months after surgery the dogs were sacrificed and block sections were taken for histologic evaluation.

Results: Histologic and histomorphometric measurements were used to evaluate new bone formation. Results from this evaluation revealed bone formation at the membrane‐only sites and the membrane‐plus‐bone grafted sites. The bone grafts were completely incorporated by the newly formed marginal compact bone. For all treated sites, there was poor bone‐to‐implant contact. Histomorphometric measurements showed a trend toward greater bone formation at membrane‐treated sites compared with control sites. However, autogenous bone grafting did not seem to affect the amount of newly regenerated bone.

Conclusions: Within the limits of this pilot project, findings show trends toward bone healing, indicating constant and enhanced bone regeneration over the exposed implant. Bone contact to the implant surface generally was poor.
Osseointegrated Implant for Single‐Tooth Replacement: A Retrospective Multicenter Study on Routine Use in Private Practice
Authors: Bianco Giuseppe , Di Raimondo Rosario , Luongo Giuseppe , Paoleschi Cesare , Piccoli Paolo , Piccoli Carlo , Rangert Bo
Published: April 2007

Background:

Implant restorations first started with total edentulism. Later, the scientific community gave its approval for restorations in partial edentulism, and only recently some studies confirmed the validity of the treatment for single‐tooth replacement.

Purpose:

The purpose of the study was to evaluate implant survival and prosthesis stability of Brånemark implants (titanium screws) when used routinely for single‐tooth replacement in all regions.

Materials and Methods:

Two hundred and fourteen patients received 252 implants for single‐tooth replacement over a period of 8 years at five private clinics in Italy. The patients were treated in accordance with the protocol for Brånemark implants, and the data gathered have been analyzed according to established evaluation methods.

Results:

During the observation period, 10 failures were recorded and 229 restorations were carried out. After the first year of loading, the total cumulative survival rate (CSR) was 96%, which then remained stable over the study time. The most frequent complication was loosening of the abutment screws (n = 22), amounting to 35% of all of the complications. This problem was related mainly to earlier types of abutments, whereas the more recent design, CeraOne abutment, showed a low frequency of screw loosening.

Conclusions:

The high survival rate, which is similar to that presented for prospective multicenter studies for single‐tooth restorations with Brånemark implants, led to the conclusion that the use of this treatment modality is a reliable treatment for routine use in all oral regions.
Clinical Experiences of CNC‐Milled Titanium Frameworks Supported by Implants in the Edentulous Jaw: 1‐Year Prospective Study
Authors: Örtorp Anders , Jemt Torsten
Published: April 2007

Background: A new type of titanium framework has been introduced, but so far no clinical reports have been made in this treatment modality.

Purpose: The aim of this study was to report the clinical performance of implant‐supported prostheses with computer numeric controlled (CNC)‐milled titanium frameworks in the edentulous jaw and to compare the results with prostheses provided with conventional cast frameworks during the first year of function.

Material and Methods: A consecutive group of 65 patients with 67 prostheses were provided with CNC‐milled titanium frameworks in 23 upper and 44 lower jaws. During the same period, 61 consecutive patients were treated on a routine basis with 31 upper and 31 lower conventional gold alloy casting prostheses. Clinical and radiographic 1‐year data were collected for both the test and control groups.

Results: A total of 14 of 729 inserted implants were lost during the follow‐up period (1.9%). All prostheses were functioning after 1 year except a conventional prosthesis with a cast framework, which was replaced by an implant‐supported over‐denture due to implant loss. The 1‐year cumulative survival rate (CSR) was 100% and 97.8% for CNC prostheses and implants, respectively. The corresponding CSR for the control group was 98.3% and 98.3%, respectively. Few problems were reported in both groups, and the clinical and the radiologic performances were similar for both groups. No mechanical complications except some resin veneer fractures (n = 6) were observed. The mean marginal bone loss for the test group during the first year in function was 0.4 mm (SD = 0.35) and 0.4 mm (SD = 0.33) in the upper and lower jaws, respectively. A similar pattern of bone reaction was also observed in the control group.

Conclusion: CNC‐milled titanium frameworks can be used as an alternative to conventional castings in the edentulous jaw, presenting similar clinical and radiologic performances as conventional cast frameworks during the first year of function.
Marginal Bone Level around Implants Assessed in Digital and Film Radiographs: In Vivo Study in the Dog
Authors: Borg Eva , Gröndahl Kerstin , Persson Leif G. , Gröndahl Hans‐Göran
Published: April 2007

Background: One of the objectives of postoperative radiographic examinations of implants is to evaluate the marginal bone height and its changes over time.

Purpose: The purpose of this study was to assess the influence of digital image processing on measurements of the marginal bone level around implants.

Material and Methods: Implants in beagle dogs, used to study the development of peri‐implantitis and subsequent healing following treatment, were monitored with conventional radiography and a digital image plate system. Five observers measured the distance between a reference point and the bone level. Measurements in conventional radiographs were made with the use of an x‐ray viewer (2X) and a magnifying lens (7X). For the digital images, the system's built‐in measuring function was used together with five image processing techniques: edge enhancement (matrixes set on 5 and 25), inverted grey scale, single color highlight, and color intensity mapping together with the brightness and contrast control. From the time of maximum breakdown and the end of the experiment, histologic values were available.

Results: Differences between techniques and observers increased toward the end of the healing period. Measurements made at maximum breakdown did not differ significantly from the histologic value. Measurements made after healing all methods, except that using edge enhancement and a 25 × 25 kernel, differed significantly from the histologic value by underestimating the bone level.

Conclusions: Measurements of bone level around implants from digital radiographs are as accurate and precise as those from film images. In particular cases, the use of specific image processing algorithms may improve both accuracy and precision. After healing, the histologic specimens showed an incomplete bone fill in the crater with a remaining thin layer of connective tissue in contact with the fixture, and in such situations, the morphology of the bone will give a more complicated diagnostic task.
A Histomorphometric and Biomechanical Study of the Effect of Delayed Titanium Implant Placement in Irradiated Rabbit Bone
Authors: Johnsson Åse A. , Sawaii Toshihiro , Jacobson Magnus , Granström Gösta , Turesson Ingela
Published: April 2007

Background: The time interval from irradiation to implant surgery has been considered an impact factor for implant integration in irradiated bone and the importance of a long interval between the radiation trauma and reconstructive bone surgery has been suggested.

Purpose: The present study was undertaken to histomorphometrically and biomechanically analyze the effect of delayed implant placement on bone healing around titanium implants in irradiated bone.

Materials and Methods: Rabbits were given a single dose of 15 Gy Cobalt60 radiation to one hind leg, the other hind leg serving as a control. Titanium screws were inserted into the femur and tibia directly and at 12 weeks and 52 weeks after irradiation. The implants were evaluated after a healing time of 8 weeks. The torques necessary for removal of the implants were measured. Histomorphometry with respect to bone‐metal contact and amount of bone surrounding the implants was performed.

Results: The biomechanical force necessary to unscrew the titanium implants in the irradiated bone was significantly increased after a resting period of 1 year between irradiation and implant placement, compared to direct implant placement. The histornorphometric evaluation showed an improvement of bone healing around the implants in the irradiated bone, both after a resting period of 12 weeks and after 1 year compared to direct implant placement.

Conclusions: It is concluded that a relatively long interval between irradiation and reconstructive bone surgery will improve osseointegration of titanium implants in irradiated rabbit bone.
Brånemark System® Wide Platform Implants for Single Molar Replacement: Clinical Evaluation of Prospective and Retrospective Materials
Authors: Polizzi Giovanni , Rangert Bo , Lekholm Ulf , Gualini Frederico , Lindström Håkan
Published: April 2007

Background: The use of oral implants for single tooth replacement has become a predictable treatment modality. As single tooth loss is most common in posterior areas of the jaws, the use of the protocol is of specific interest in those regions. New implant designs aimed at this purpose have also been introduced.

Purpose: The aim of the study was to present the outcomes for wide diameter implant treatment when being used in posterior areas of the jaws.

Materials and Methods: This paper presents the 3‐year results of a prospective multicenter study (three clinics; n = 38 implants) and the 1‐year results from a retrospective multicenter study (two clinics; n = 20 implants) on wide diameter implants for single molar replacement. Based on the hypothesis that dense bone in posterior mandibles would benefit from careful surgery and longer remodeling time, the influences of surgical technique and healing time on implant success and bone resorption were particularly addressed.

Results: The outcome demonstrated a good predictability for Brånemark System® Wide Platform implants, at least short term, when used as single molar support (prospective group cumulative success rate [CSR] = 92% after 3 years; retrospective group CSR = 95% after 1 year). The increased mechanical strength of the wide platform implant/abutment complex also turned out to be important for mechanical stability.

Conclusions: The study indicated that it was important to carefully perform surgery in posterior mandibles in order to preserve and optimally use the existing dense bone. It was suggested that from bone healing and remodeling aspects, posterior mandibles may be more demanding to handle than corresponding areas of maxillae.
Nonsubmerged Implants in the Treatment of the Edentulous Lower Jaw: A 5‐Year Prospective Longitudinal Study of ITI Hollow Screws
Authors: Hellem Solve , Karlsson Ulf , Almfeldt Ingvar , Brunell Gunnar , Hamp Sven‐Erik , Astrand Per
Published: April 2007

Background: Although most implant systems have been designed for a two‐stage surgical technique, a one‐stage surgical technique has always been advocated for the ITI Dental Implant System (Straumann AG, Waldenburg, Switzerland). A new generation of ITI implants was presented in 1988 and included a hollow cylinder, a hollow screw, and a solid screw.

Purpose: The goal of this study was to evaluate the one‐stage surgical technique in connection with the ITI hollow screw in a longitudinal study over 5 years.

Materials and Methods: Forty‐six patients with edentulous lower jaws were supplied with ITI hollow‐screw implants. Patients who requested an overdenture (n = 18) had four implants inserted; those who requested a fixed bridge (n = 28) had five to six implants. The patients have been followed annually for 5 years. There was a dropout of three patients (6.5%); one patient did not want to cooperate, one moved from the area, and one was deceased. The clinical examinations included bridge removal for evaluation of the individual implant stability in connection with the 1‐, 3‐, and 5‐year examinations. Radiographic examinations were performed with intraoral radiographs and the long‐cone technique.

Results: The survival rate after 5 years was 95.7%. The success rate (in which implants undergoing treatment of peri‐implantitis were not counted as successes) was 91.4%. The mean marginal bone loss between the baseline and the 1‐year examination was 0.1 mm and between the 1‐ and 5‐year examinations was 0.1 mm. These changes in marginal bone level were not significant.

Conclusions: The success rate of ITI hollow‐screw implants in the edentulous mandible was 91.4% after a 5‐year observation period. There was no significant change in mean bone level between the loading of the implants and the 5‐year examination. Peri‐implantitis was diagnosed in three patients with poor oral hygiene, and it affected six implants. Five of these failed in spite of treatment.
COHOMOLOGY SPLITTINGS OF STIEFEL MANIFOLDS
Authors: KITCHLOO NITU
Published: April 2007

The complex Stiefel manifolds admit a stable decomposition as Thom spaces of certain bundles over
Grassmannians. The purpose of the paper is to identify the splitting in any complex oriented cohomology
theory.
ON SIMPLEX SHAPE SPACES
Authors: LE HUILING , BARDEN DENNIS
Published: April 2007

The right-invariant Riemannian metric on simplex shape spaces in fact makes them particular Riemannian
symmetric spaces of non-compact type. In the paper, the general properties of such symmetric spaces
are made explicit for simplex shape spaces. In particular, a global matrix coordinate representation is
suggested, with respect to which several geometric features, important for shape analysis, have simple
and easily computable expressions. As a typical application, it is shown how to locate the Fréchet means
of a class of probability measures on the simplex shape spaces, a result analogous to that for Kendall's
shape spaces.
SOME MODEL THEORY OVER AN EXCEPTIONAL UNISERIAL RING AND DECOMPOSITIONS OF SERIAL MODULES
Authors: PUNINSKI GENNADI
Published: April 2007

An example is given of a direct summand of a serial module that does not admit an indecomposable decomposition.
A NON-SEPARABLE REFLEXIVE BANACH SPACE ON WHICH THERE ARE FEW OPERATORS
Authors: WARK H. M.
Published: April 2007

It is shown that there exists a non-separable reflexive Banach space on which every bounded linear
operator is the sum of a scalar multiple of the identity operator and an operator of separable range.
There is a strong sense that such a Banach space has as few operators as its linear and topological
properties allow.
PARTIALLY MIXING AND LOCALLY RANK 1 SMOOTH
TRANSFORMATIONS AND FLOWS ON THE TORUS Td, d [ges ] 3
Authors: FAYAD BASSAM R.
Published: April 2007

The paper gives the first examples of C∞ measure preserving flows and diffeomorphisms on the torus
that are partially mixing and have a simple spectrum.
THE MODULUS OF THE IMAGE ANNULI UNDER UNIVALENT HARMONIC MAPPINGS AND A CONJECTURE OF NITSCHE
Authors: LYZZAIK ABDALLAH
Published: April 2007

The object of the paper is to show that if f is a univalent, harmonic mapping of the annulus
A(r, 1) = {z : r < [mid ]z[mid ] < 1}
onto the annulus A(R, 1), and if s is the length of the segment of the Grötzsch ring
domain associated with A(r, 1), then R < s. This gives the first, quantitative
upper bound of R, which relates to a question of J. C. C. Nitsche that he raised in 1962.
The question of whether this bound is sharp remains open.
EXPLICIT GEOMETRY ON A FAMILY OF CURVES OF GENUS 3
Authors: GUÀRDIA J.
Published: April 2007

An explicit geometrical study of the curves

[formula here]

is presented. These are non-singular curves of genus 3, defined over ℚ(a). By exploiting their symmetries,
it is possible to determine most of their geometric invariants, such as their bitangent lines and their
period lattice. An explicit description is given of the bijection induced by the Abel–Jacobi map between
their bitangent lines and odd 2-torsion points on their jacobian. Finally, three elliptic quotients of these
curves are constructed that provide a splitting of their jacobians. In the case of the curve
[Cscr ]1±√2, which is isomorphic to the Fermat curve of degree 4, the computations yield
a finer splitting of its jacobian than the classical one.
LOGARITHMIC GROWTH FOR MATRIX MARTINGALE TRANSFORMS
Authors: GILLESPIE T. A. , POTT S. , TREIL S. , VOLBERG A.
Published: April 2007

An example is given of an operator weight W that satisfies the dyadic operator Hunt–Muckenhoupt–Wheeden condition [Aopf ]d2 for which there exists a dyadic martingale transform on L2 (W) that is unbounded.
The construction relates weighted boundedness to the boundedness of dyadic vector Hankel operators.
FINITARY AUTOMORPHISM GROUPS OVER NON-COMMUTATIVE RINGS
Authors: WEHRFRITZ B. A. F.
Published: April 2007

The notion of a group of finitary automorphisms of an arbitrary module over an arbitrary ring is
introduced, and it is shown how properties of such groups can be derived from the case where the ring
is a division ring (that is, from the properties of finitary skew linear groups). The results are particularly
strong if either the group is locally finite or the module is Noetherian.
WEAK SLICE CONDITIONS AND HÖLDER IMBEDDINGS
Authors: BUCKLEY STEPHEN M. , STANOYEVITCH ALEXANDER
Published: April 2007

Weak slice conditions are introduced and imbeddings of Sobolev spaces in various Lipschitz-type spaces
are investigated.
SOME RESULTS ON THE OBERWOLFACH PROBLEM
Authors: HILTON A. J. W. , JOHNSON MATTHEW
Published: April 2007

The well-known Oberwolfach problem is to show that it is possible to 2-factorize Kn (n odd) or Kn less
a 1-factor (n even) into predetermined 2-factors, all isomorphic to each other; a few exceptional cases
where it is not possible are known. A completely new technique is introduced that enables it to be shown
that there is a solution when each 2-factor consists of k r-cycles and one (n−kr)-cycle for all n [ges ] 6kr−1.
Solutions are also given (with three exceptions) for all possible values of n when there is one r-cycle,
3 [les ] r [les ] 9, and one (n−r)-cycle, or when there are two r-cycles, 3 [les ] r [les ] 4, and one (n−2r)-cycle.
ENTROPY NUMBERS OF DIAGONAL OPERATORS BETWEEN VECTOR-VALUED SEQUENCE SPACES
Authors: KÜHN THOMAS , SCHONBEK TOMAS P.
Published: April 2007

Upper and lower bounds are established for the entropy numbers of certain diagonal operators between
Banach sequence spaces. These diagonal operators are isomorphisms between the spaces considered in
the paper and weighted sequence spaces considered by Leopold so that the entropy numbers in question
coincide with those considered by Leopold. The results in the paper improve the previous results in at
least two ways. The estimates in the paper are ‘almost’ sharp in the sense that the upper and lower
estimates differ only by logarithmic factors for a much wider range of parameters. Moreover, all the
upper estimates are improvements on the previous ones, the improvement being quite significant in some
cases.
Parabolic Trough Optical Performance Analysis Techniques
Authors: Lüpfert Eckhard , Pottler Klaus , Ulmer Steffen , Riffelmann Klaus-J. , Neumann Andreas , Schiricke Björn
Published: April 2007

Analysis of geometry and optical properties of solar parabolic trough collectors uses a number of specific techniques that have demonstrated to be useful tools in prototype evaluation. These are based on photogrammetry, flux mapping, ray tracing, and advanced thermal testing. They can be used to assure the collector quality during construction and for acceptance tests of the solar field. The methods have been applied on EuroTrough collectors, cross checked, and compared. This paper summarizes results in collector shape measurement, flux measurement, ray tracing, and thermal performance analysis for parabolic troughs. It is shown that the measurement methods and the parameter analysis give consistent results. The interpretation of the results and their annual evaluation give hints on identified relevant improvement potentials for the following generation of solar power plant collectors.
Hydrogen From Solar Via Light-Assisted High-Temperature Water Splitting Cycles
Authors: T-Raissi A. , Muradov N. , Huang C. , Adebiyi O.
Published: April 2007

Hydrogen production from solar-driven thermochemical water splitting cycles (TCWSCs) provides an approach that is energy efficient and environmentally attractive. Of particular interest are TCWSCs that utilize both thermal (i.e., high temperature) and light (i.e., quantum) components of the solar resource, boosting the overall solar-to-hydrogen conversion efficiency compared to those with heat-only energy input. We have analyzed two solar-driven TCWSCs: (1) carbon dioxide (CO2)/carbon monoxide cycle; and (2) sulfur dioxide (SO2)/sulfuric acid cycle. The first cycle is based on the premise that CO2 becomes susceptible to near-ultraviolet and even visible radiation at high temperatures (greater than 1300K). The second cycle is a modification of the well-known Westinghouse hybrid cycle, wherein the electrochemical step is replaced by a photocatalytic step. At the Florida Solar Energy Center (FSEC), a novel hybrid photo-thermochemical sulfur-ammonia (S–A) cycle has been developed. The main reaction (unique to FSEC’s S–A cycle) is the light-induced photocatalytic production of hydrogen and ammonium sulfate from an aqueous ammonium sulfite solution. Ammonium sulfate product is processed to generate oxygen and recover ammonia and SO2 that are then recycled and reacted with water to regenerate the ammonium sulfite. Experimental data for verification of the concept are provided.
Experimental Validation of the Laboratory Air Handling Unit System (LAHU)—Part I: Winter Operation
Authors: Cui Yujie , Liu Mingsheng , Conger Kirk
Published: April 2007

The laboratory air handling unit (LAHU) system for laboratory buildings has been developed and optimized. Theoretical study has concluded that the LAHU with optimal outside air control and optimal heat recovery control significantly reduces thermal energy use, saves pump power consumption and improves office indoor air quality. This paper presents validation experiments of the LAHU energy performance for the winter operation in a large university research building including detailed experimental methodology, procedures and experimental energy savings results. The experiments establish that the LAHU can reduce annual heating energy consumption by over 30% and can reduce heat recovery pump power by over 50%peryear for this typical laboratory building. The experimental validation of the LAHU for the summer operation will be reported in a followup paper.
Mice Lacking Components of Adaptive Immunity Show Increased
Brucella abortus virB
Mutant Colonization
Authors: Rolán Hortensia García , Tsolis Renée M.
Published: April 2007

The
Brucella abortus
type IV secretion system (T4SS), encoded by the
virB
genes, is essential for survival in mononuclear phagocytes in vitro. In the mouse model, a
B. abortus virB
mutant was initially able to colonize the spleen at the level of the wild type for approximately 3 to 5 days, which coincided with the development of adaptive immunity. To investigate the relationship between survival in macrophages cultivated in vitro and persistence in tissues in vivo, we tested the ability of mutant mice lacking components of adaptive immunity to eliminate the
virB
mutant from the spleen during a mixed infection with the
B. abortus
wild type.
Ifng
−/−
or β

2

m
−/−
mice were able to clear the
virB
mutant to the same degree as control mice. However, spleens of
Rag1
−/−
mice and
Igh6
−/−
mice were more highly colonized by the
virB
mutant than control mice after 14 to 21 days, suggesting that, in these mice, there is not an absolute requirement for the T4SS to mediate persistence of
B. abortus
in the spleen. Macrophages isolated from
Igh6
−/−
mice killed the
virB
mutant to the same extent as macrophages from control mice, showing that the reduced ability of these mice to clear the
virB
mutant from the spleen does not correlate with diminished macrophage function in vitro. These results show that in the murine model host, the T4SS is required for persistence beyond 3 to 5 days after infection and suggest that the T4SS may contribute to evasion of adaptive immune mechanisms by
B. abortus
.
Phenetic relationships among different races of Striga gesnerioides (Willd.) Vatke from West Africa
Authors: Botanga Christopher J. , Timko Michael P.
Published: April 2007

Striga gesnerioides is a root hemiparasite that primarily parasitizes dicotyledonous species, including cowpea ( Vigna unguiculata L.) and other legumes. Based on the differential resistance response of various cultivars, landraces, and breeding lines, it has been proposed that several distinct races of cowpea-parasitic S. gesnerioides exist in West Africa. In this study, we used amplified fragment length polymorphism profile analysis to examine the genetic variability within and among populations of cowpea-parasitic S. gesnerioides within the suspected distribution range of a particular race, and statistical clustering methods to define the phenetic relationships of the various races in West Africa. Our data indicate that genetic variability within and among populations of each of the previously recognized races of cowpea-parasitic S. gesnerioides is extremely low. On the basis of genotypic profile and host differential resistance responses, 2 previously unknown races were identified. Of the 7 races now identifiable, races SG1 (from Burkina Faso) and SG5 (from Cameroon) are the most closely related, and SG4 (from Benin) and SG3 (from Niger/Nigeria) are the most divergent. SG6, a new race of the parasite identified in Senegal, was found to be the most genetically similar to SG4 from Benin. We also demonstrate that a hypervirulent isolate of the S. gesnerioides from Zakpota, in the Republic of Benin, is genotypically distinct from other populations of SG4, thereby warranting designation as a separate race, which we called SG4z. To further support our race classification scheme, we identified a group of molecular markers that effectively discriminate each of the various races. Finally, we show that an isolate (designated SG4i) of the wild legume Indigofera hirsuta –parasitic S. gesnerioides is genetically distinct and significantly diverged from the various races of cowpea-parasitic S. gesnerioides. Our data suggest that both geographic isolation and host-driven selection are critical factors defining race formation in S. gesnerioides in West Africa.
Seed and agronomic QTL in low linolenic acid, lipoxygenase-free soybean (Glycine max(L.) Merrill) germplasm
Authors: Reinprecht Yarmilla , Poysa Vaino W. , Yu Kangfu , Rajcan Istvan , Ablett Gary R. , Pauls K. Peter
Published: April 2007

Linolenic acid and seed lipoxygenases are associated with off flavours in soybean products. F5recombinant inbred lines (RILs) from a cross between a low linolenic acid line (RG10) and a seed lipoxygenase-free line (OX948) were genotyped for simple sequence repeats (SSR), random amplified polymorphic DNA (RAPD), sequence-tagged sites (STS), and cleaved amplified polymorphic sequence (CAPS) markers and evaluated for seed and agronomic traits at 3 Ontario locations in 2 years. One hundred twenty markers covering 1247.5 cM were mapped to 18 linkage groups (LGs) in the soybean composite genetic map. Seed lipoxygenases L-1 and L-2 mapped as single major genes to the same location on LG G13-F. L-3 mapped to LG G11-E. This is the first report of a map position for L-3. A major quantitative trait locus (QTL) associated with reduced linolenic acid content was identified on LG G3-B2. QTLs for 12 additional seed and agronomic traits were detected. Linolenic acid content, linoleic acid content, yield, seed mass, protein content, and plant height QTL were present in at least 4 of 6 environments. Three to 8 QTLs per trait were detected that accounted for up to 78% of total variation. Linolenic acid and lipoxygenase loci did not overlap yield QTL, suggesting that it should be possible to develop high-yielding lines resistant to oxidative degradation by marker-assisted selection (MAS).
Mapping of major spot-type and net-type net-blotch resistance genes in the Ethiopian barley line CI 9819
Authors: Manninen O.M. , Jalli M. , Kalendar R. , Schulman A. , Afanasenko O. , Robinson J.
Published: April 2007

Net blotch of barley ( Hordeum vulgare L.), caused by the fungal phytopathogen Pyrenophora teres Drechs. f. teres Smedeg., constitutes one of the most serious constraints to barley production worldwide. Two forms of the disease, the net form, caused by P. teres f. teres, and the spot form, caused by P. teres f. maculata, are differentiated by the type of symptoms on leaves. Several barley lines with major gene resistance to net blotch have been identified. Earlier, one of these was mapped in the Rolfi × CI 9819 cross to barley chromosome 6H, using a mixture of 4 Finnish isolates of P. teres f. teres. In this study, we used the same barley progeny to map resistance to 4 spot-type isolates and 4 net-type isolates of P. teres. With all net-type isolates, a major resistance gene was located on chromosome 6H, in the same position as described previously, explaining up to 88% of the phenotypic variation in infection response in the progeny. We designate this gene Rpt5. Several minor resistance genes were located on chromosomes 1H, 2H, 3H, 5H, and 7H. These minor genes were not genuinely isolate-specific, but their effect varied among isolates and experiments. When the spot-type isolates were used for infection, a major isolate-specific resistance gene was located on chromosome 5H, close to microsatellite marker HVLEU, explaining up to 84% of the phenotypic variation in infection response in the progeny. We designate this gene Rpt6. No minor gene effects were detected in spot-type isolates. The Ethiopian 2-rowed barley line CI 9819 thus carries at least 2 independent major genes for net-blotch resistance: Rpt5, active against net-type isolates; and Rpt6, active against specific spot-type isolates.
Microsatellite markers are powerful tools for discriminating among olive cultivars and assigning them to geographically defined populations
Authors: Sarri V. , Baldoni L. , Porceddu A. , Cultrera N.G.M. , Contento A. , Frediani M. , Belaj A. , Trujillo I. , Cionini P.G.
Published: April 2007

Twelve simple sequence repeat (SSR) loci were used to differentiate among 118 cultivars sampled in several countries of the Mediterranean basin and to analyze the genetic structure of olive cultivar gene pools. The markers were found to have high discrimination power. On average, with a single assay it was possible to discriminate 96% of the pairwise comparisons and, with a combination of 3 loci, virtually all cultivars were distinguished. The SSR markers were also tested for their ability to assign cultivars to their geographic population of origin. A selection of 6 loci was found to maximize assignment accuracy, correctly reallocating up to 75.4% of cultivars to their population of origin. Because of the confusion surrounding the origin of most olive cultivars, their molecular identification and ascertainment of origin will be extremely useful for germplasm management and breeding.
Genetic susceptibility to heart disease in Canada: lessons from patients with familial hypercholesterolemia
Authors: Hegele Robert A.
Published: April 2007

Much of the recent progress in treating patients with heart disease due to narrowed coronary arteries has resulted from studying disease evolution in patients with rare monogenic forms of disease. For instance, autosomal dominant familial hypercholesterolemia (FH, MIM (Mendelian Inheritance in Man) 143890) typically results from heterozygous mutations in LDLR encoding the low-density lipoprotein (LDL) receptor. Deficient LDLR activity results in elevated circulating LDL cholesterol, which accumulates within blood vessel walls, forming arterial plaques that can grow and eventually occlude the arterial lumen. Heterozygous LDLR mutations are usually detected using exon-by-exon sequence analysis (EBESA) of genomic DNA, a technology that has identified ~50 mutations in heterozygous FH (HeFH) subjects in Ontario. However, ~35% of Ontario HeFH patients had no EBESA-identified LDLR mutation. The diagnostic gap relates both to the genetic heterogeneity of FH and also to inadequate sensitivity of EBESA to detect certain mutation types, such as large deletions or insertions in LDLR. By means of a dedicated method to detect copy number variations (CNVs), additional heterozygous mutations in LDLR ranging from ~500 to >15 000 bases were uncovered, accounting for most of the remainder of Ontario HeFH patients. The appreciation of the key role of genomic CNVs in disease coincides with recent genome-wide mapping studies demonstrating that CNVs are common in apparently healthy people. CNVs thus represent a new level of genomic variation that is both an important mechanism of monogenic disease and a contributor to genomic variation in the general population; as well, it may have implications for evolution, biology, and possibly susceptibility to common complex diseases.
UPDATE-EFFICIENT DATA STRUCTURES FOR DYNAMIC IP ROUTER TABLES
Authors: LAUER TOBIAS , OTTMANN THOMAS , DATTA AMITAVA
Published: April 2007

We show that two data structures, min-augmented range tree and priority search pennant, efficiently support all the required operations for updatable IP router tables and argue that both structures are better suited for the one-dimensional dynamic IP lookup problem than the priority search tree (PST) used in a previous solution. It is possible to maintain both structures in time O(1) after a rotation, while PST with n elements may require Ω( log n) steps for a single rotation. Therefore, the proposed structures can be balanced using a larger class of rebalancing schemes compared to PST. Both structures are also of interest independently of the IP lookup problem and may be used as attractive implementations of priority search queues in other contexts as well.
USING RESTRICTED RANDOM WALKS FOR LIBRARY RECOMMENDATIONS AND KNOWLEDGE SPACE EXPLORATION
Authors: FRANKE MARKUS , GEYER-SCHULZ ANDREAS
Published: April 2007

Implicit recommender systems provide a valuable aid to customers browsing through library corpora. We present a method to realize such a recommender especially for, but not limited to, libraries. The method is cluster-based, scales well for large collections, and produces recommendations of good quality. The approach is based on using session histories of visitors of the library's online catalog in order to generate a hierarchy of nondisjunctive clusters. Depending on the user's needs, the clusters at different levels of the hierarchy can be employed as recommendations. Using the prototype of a user interface we show that, if, for instance, the user is willing to sacrifice some precision in order to gain a higher number of documents during a specific session, he or she can do so easily by adjusting the cluster level via a slider.
A NEW FEATURE SELECTION METHOD FOR TEXT CLASSIFICATION
Authors: UCHYIGIT GULDEN , CLARK KEITH
Published: April 2007

Text classification is the problem of classifying a set of documents into a pre-defined set of classes. A major problem with text classification problems is the high dimensionality of the feature space. Only a small subset of these words are feature words which can be used in determining a document's class, while the rest adds noise and can make the results unreliable and significantly increase computational time. A common approach in dealing with this problem is feature selection where the number of words in the feature space are significantly reduced.

In this paper we present the experiments of a comparative study of feature selection methods used for text classification. Ten feature selection methods were evaluated in this study including the new feature selection method, called the GU metric. The other feature selection methods evaluated in this study are: Chi-Squared (χ2) statistic, NGL coefficient, GSS coefficient, Mutual Information, Information Gain, Odds Ratio, Term Frequency, Fisher Criterion, BSS/WSS coefficient. The experimental evaluations show that the GU metric obtained the best F1 and F2 scores. The experiments were performed on the 20 Newsgroups data sets with the Naive Bayesian Probabilistic Classifier.