Vipp1 deletion mutant of Synechocystis: A connection between bacterial phage shock and thylakoid biogenesis?

Plant chloroplasts originated from an endosymbiotic event by which an ancestor of contemporary cyanobacteria was engulfed by an early eukaryotic cell and then transformed into an organelle. Oxygenic photosynthesis is the specific feature of cyanobacteria and chloroplasts, and the photosynthetic machinery resides in an internal membrane system, the thylakoids. The origin and genesis of thylakoid membranes, which are essential for oxygenic photosynthesis, are still an enigma. Vipp1 (vesicle-inducing protein in plastids 1) is a protein located in both the inner envelope and the thylakoids of Pisum sativum and Arabidopsis thaliana. In Arabidopsis disruption of the VIPP1 gene severely affects the plant's ability to form properly structured thylakoids and as a consequence to carry out photosynthesis. In contrast, Vipp1 in Synechocystis appears to be located exclusively in the plasma membrane. Yet, as in higher plants, disruption of the VIPP1 gene locus leads to the complete loss of thylakoid formation. So far VIPP1 genes are found only in organisms carrying out oxygenic photosynthesis. They share sequence homology with a subunit encoded by the bacterial phage shock operon (PspA) but differ from PspA by a C-terminal extension of about 30 amino acids. In two cyanobacteria, Synechocystis and Anabaena, both a VIPP1 and a pspA gene are present, and phylogenetic analysis indicates that VIPP1 originated from a gene duplication of the latter and thereafter acquired its new function. It also appears that the C-terminal extension that discriminates VIPP1 proteins from PspA is important for its function in thylakoid formation.

Molecular markers reveal that population structure of the human pathogen Candida albicans exhibits both clonality and recombination.

The life history of Candida albicans presents an enigma: this species is thought to be exclusively asexual, yet strains show extensive phenotypic variation. To address the population genetics of C. albicans, we developed a genetic typing method for codominant single-locus markers by screening randomly amplified DNA for single-strand conformation polymorphisms. DNA fragments amplified by arbitrary primers were initially screened for single-strand conformation polymorphisms and later sequenced using locus-specific primers. A total of 12 single base mutations and insertions were detected from six out of eight PCR fragments. Patterns of sequence-level polymorphism observed for individual strains detected considerable heterozygosity at the DNA sequence level, supporting the view that most C. albicans strains are diploid. Population genetic analyses of 52 natural isolates from Duke University Medical Center provide evidence for both clonality and recombination in C. albicans. Evidence for clonality is supported by the presence of several overrepresented genotypes, as well as by deviation of genotypic frequencies from random (Hardy-Weinberg) expectations. However, tests for nonrandom association of alleles across loci reveal less evidence for linkage disequilibrium than expected for strictly clonal populations. Although C. albicans populations are primarily clonal, evidence for recombination suggests that sexual reproduction or some other form of genetic exchange occurs in this species.

Apoptosis and APC in colorectal tumorigenesis.

Tumors result from disruptions in the homeostatic mechanisms that regulate cell birth and cell death. In colon cancer, one of the earliest manifestation of this imbalance is the formation of polyps, caused by somatic and inherited mutations of the adenomatous polyposis coli (APC) tumor suppressor gene in both humans and mice. While the importance of APC in tumorigenesis is well documented, how it functions to prevent tumors remains a mystery. Using a novel inducible expression system, we show that expression of APC in human colorectal cancer cells containing endogenous inactive APC alleles results in a substantial diminution of cell growth. Further evaluation demonstrated that this was due to the induction of cell death through apoptosis. These results suggest that apoptosis plays a role not only in advanced tumors but also at the very earliest stages of neoplasia.

Organismal duplication, inclusive fitness theory, and altruism: understanding the evolution of endosperm and the angiosperm reproductive syndrome.

For almost a century, events relating to the evolutionary origin of endosperm, a unique embryo-nourishing tissue that is essential to the reproductive process in flowering plants, have remained a mystery. Integration of recent advances in phylogenetic reconstruction, comparative reproductive biology, and genetic theory can be used to elucidate the evolutionary events and forces associated with the establishment of endosperm. Endosperm is shown to be derived from one of two embryos formed during a rudimentary process of "double fertilization" that evolved in the ancestors of angiosperms. Acquisition of embryo-nourishing behavior (with accompanying loss of individual fitness) by this supernumerary fertilization product was dependent upon compensatory gains in the inclusive fitness of related embryos. The result of the loss of individual fitness by one of the two original products of double fertilization was the establishment of endosperm, a highly modified embryo/organism that reproduces cryptically through behavior that enhances the fitness of its associated embryo within a seed. Finally, although triploid endosperm remains a synapomorphy of angiosperms, inclusive fitness analysis demonstrates that the embryo-nourishing properties of endosperm initially evolved in a diploid condition.

Psychological and Social Perspectives on Malingering and Symptom Exaggeration: Conceptualization and Interventions Using Acceptance and Commitment Therapy

Malingering and the production of false symptoms seen in such disorders as Factitious Disorder are an ongoing mystery to medical and mental health professionals. Historically, these presentations have been difficult to identify and treat. As might be expected, individuals with such symptomology rarely agree to participate in research, possibly because of a reluctance to admit to the feigning or exaggerating behaviors and a fear of reprisals. Many different etiologies have been proposed, including the assumption of roles in order to manage impressions, taking control of symptoms in order to gain attention or other rewards or avoid aversive events, and even the production of symptoms that is largely out of awareness such as is seen in conversion or somatoform presentations. By examining historical and present-day beliefs about etiology and treatment interventions, professionals can explore what new types of effective treatment might look like. The behaviorist philosophy that underlies Acceptance and Commitment Therapy proposes a perspective emphasizing effective working in context. This philosophy also suggests individuals sometimes engage in behavior in order to escape from or avoid aversive experiences. Utilizing case examples and fresh behavioral perspectives provides insight and ideas for conceptualization of these behaviors of interest. Using the above conceptualizations, an ACT based treatment of those who produce false symptoms is introduced.

Surréalisme Sous-L’Eau : science and surrealism in the early films and writings of Jean Painlevé

A French biologist who moved in Surrealist circles, Jean Painlevé began making films about underwater creatures in 1927, and by 1982 had created over two hundred films on a broad range of natural, scientific, and political subjects. His underwater films remain the most ethereal and poetic works in his oeuvre, and he specifically used cinema to capture the mystery and wonder of nature.

Postmortem/postpartum : the intersection between fertility and Mochican ancestral power

With no written record, the religious beliefs of the Pre-Columbian Mochica civilization are much of a mystery. This paper attempts to decipher the position of the deceased Mochicans, also known as ancestors, within the society as a whole. It discusses the ways in which we can use multiple sources of information, archaeological, iconographic, ethnohistoric and ethnographic to learn about the various aspects of Mochican culture. Specifically I will use these methods for collecting data to examine at how the Mochica viewed their deceased and to argue that part of the Mochica religious system granted their dead a supernatural ability to control human and agricultural fertility. This power would give Mochican ancestors a significant place within the society.

El Castellar d’Elx: enigma, proyecto, documento

El proyecto de investigación arqueológica sobre el yacimiento ilicitano del Castellar d’Elx tiene como objetivo documentar, quizá, uno de los yacimientos arqueológicos más interesantes, controvertidos y olvidados que el panorama de la arqueología islámica puede ofrecer en la provincia de Alicante. La investigación ha sido impulsada por el Museo Arqueológico de Alicante (MARQ), con la participación de la Universidad de Alicante y el apoyo del Museo Arqueológico y de Historia de Elche (MAHE). Su objetivo primordial es la explicación histórica del asentamiento a la luz de los convulsos procesos de la formación de una sociedad islámica entre los siglos VIII y X, entre los que se sitúa la problemática de la localización del topónimo árabe al-‘Askar (el campamento), citado por el geógrafo oriental al-Ya’qûbi en su obra Kitab al-buldan, fechada a finales del siglo IX.

Short nomenclator or vocabular in English and Hebrew: composed alphabetically for the use and benefit of my pupils in particular and for the advantage of those who are desirous to obtain the knowledge of the Hebrew tongue in general, which may be that great help to understand not only ye sacred oracles in their original, but even any Jewish author (so far as concern owns) as also it may give great insight in ye tongue to those, as to compose it, a work altogether new, [ca. 1735]

Headed on the first page with the words "Nomenclatura hebraica," this handwritten volume is a vocabulary with the Hebrew word in the left column, and the English translation on the right. While the book is arranged in sections by letter, individual entries do not appear in strict alphabetical order. The small vocabulary varies greatly and includes entries like enigma, excommunication, and martyr, as well as cucumber and maggot. There are translations of the astrological signs at the end of the volume. Poem written at the bottom of the last page in different hand: "Women when good the best of saints/ that bright seraphick lovely/ she, who nothing of an angel/ wants but truth & immortality./ Verse 2: Who silken limbs & charming/ face. Keeps nature warm."

Aviation English: Structure and Importance of an International Airborne Language

In today’s globalized world, air travel is one of the fastest growing markets. Millions of aircrafts take off and then touch down all around the world each day. This well-synchronized symphony, however, is much more complex than it seems, and communication – language - plays a crucial role during a plane’s journey. Misunderstandings and miscommunications can have disastrous effects, so the adoption of a standard phraseology to be used during flight is a means to overcome language barriers, avoid ambiguous expressions and guarantee a safe and effective operation of an aircraft. Little is known about the interaction that goes on between pilots and air traffic controllers (ATCOs), and even though the language of aviation is English, cockpit communication can be hard to understand for people who are not familiar with this specific language. The scope of this thesis is to examine the origins of this uncommon language, the characteristics and peculiarities of air communication and to shed a little light on this mystery called Aviation English.

Calcareous nannofossils of ODP Sites 149-897 and 149-901

Mesozoic calcareous nannofossil assemblages recovered during Ocean Drilling Program Leg 149 from the Iberia Abyssal Plain off the coast of Portugal were examined to determine the age of the rifting processes that affected the western Iberia Margin. Dark carbonaceous claystones (black shales) recovered from Site 901 contain highly diverse and abundant Tithonian calcareous nannofossil assemblages. Careful examination and documentation of this material has extended the ranges of numerous Jurassic and Cretaceous species and detailed a significant Late Jurassic assemblage turnover observed in the calcareous nannofossil record. The Lower Cretaceous sequence consists of intervals of serpentinized peridotite intercalated between various breccias and dark claystones. With the exception of a few samples, calcareous nannofossils are few and moderately preserved. The age of nannofossils within these varied sedimentary lithologies ranges from the late Barremian to the late Aptian. Eight new species are described: Ansulasphaera covingtonii, Clepsilithus meniscus, Conusphaera sinespina, Crepidolithus parvulus, Diazomatholithus galicianus, Percivalia arata, Rotelapillus pleoseptatus, and Tranolithus incus. Also proposed are five new combinations.

The mystery of pain : a book for the sorrowful /

Mode of access: Internet.

The avalanche : a mystery story /

Mode of access: Internet.

Christmas mystery.

Mode of access: Internet.

The second floor mystery; photoplay title of The agony column ...

Mode of access: Internet.