bluuebunny/crossref_metadata_2025 huggingface dataset:
INFLUENCE OF SEEDING DATES, SEEDING RATES, AND FERTILIZERS ON TWO CULTIVARS OF BARLEY
Authors: McFADDEN A. D.
Published: March 2010

Two commercially suitable barley cultivars were compared for three years at different dates and rates of seeding and fertility levels. Conquest was significantly higher in yield than Olli and the differential magnitude increased as seeding was delayed. Olli matured 5 days earlier than Conquest when seeded early and 9 days earlier when seeded late. The two cultivars gave the same response to seeding rates and fertilizer treatments, and yields from seeding rates were not differentially affected by fertilizer treatments. The seeding rate of 67 kg/ha, considerably below the average used in practice, gave the highest yields. There were no significant differences in unit volume or kernel weights attributable to different treatments. The results indicated that the use of Conquest in a delayed seeding program could markedly increase the unit area production in central Alberta.
REACTION OF TWO BARLEY CULTIVARS TO A PERIOD OF SOIL WATER STRESS DURING HEADING
Authors: WELLS S. A. , DUBETZ S.
Published: March 2010

Two cultivars of barley (Hordeum vulgare L.) grown at three levels of soil fertility in lysimeters protected from natural precipitation by an automatic rain shelter were subjected to two levels of soil water stress at heading time. At all levels of fertility, reductions in yield of Compana resulting from stress were proportionately smaller than those of Betzes, but the difference between cultivars was greatest when no fertilizer was applied. This differential response resulted primarily from a substantial decrease in kernel size of Betzes but a slight increase in that of Compana due to soil water stress. The number of tillers and number of kernels per spike of each cultivar were affected about equally.
CHANGES IN THE NITROGENOUS COMPONENTS OF RAPESEED (BRASSICA NAPUS) GROWN ON A NITROGEN AND SULFUR DEFICIENT SOIL
Authors: FINLAYSON A. J. , CHRIST C. M. , DOWNEY R. K.
Published: March 2010

The analyses for the amounts of nitrogenous constituents of rapeseed (Brassica napus L.) grown under conditions of nutrient deficiency have shown that additions of ammonium nitrate (44.8 kg of N/ha), triple superphosphate (22.4 kg of P2O5/ha), and potassium sulfate (205.1 kg of K2O and 89.6 kg of S/ha) to the soil increase the amounts of protein deposited in mature seed and produce changes in the relative proportions of the nitrogen-containing seed components.
PASTURE ATTRIBUTES OF ALTAI WILD RYEGRASS
Authors: Lawrence T. , Heinrichs D. H.
Published: March 2010

not available
NEEPAWA HARD RED SPRING WHEAT
Authors: Campbell A. B.
Published: March 2010

not available
A MINIRHIZOTRON FOR IN SITU OBSERVATION OF SEEDLING DEVELOPMENT
Authors: McElgunn J. D. , Lawrence T.
Published: March 2010

not available
Educational needs of foundation doctors caring for dying patients
Authors: Linklater GT
Published: March 2010

The aim of this study was to identify the educational needs of year one North of Scotland foundation doctors caring for dying patients. A postal questionnaire approach was used. The results from the questionnaire (79/132 respondents) confirmed that year one foundation doctors are frequently exposed to patient death, with 61% finding their most memorable patient death to be emotionally distressing. A quarter (26%) of respondents had recent experience of significant personal bereavement. Communicating with patients and relatives at the end of life, concerns about overtreatment and lack of senior support were highlighted as particularly difficult issues. Educational needs of the foundation doctors were identified, emphasising the importance of emotional, analytical and personal competencies.
An unusual cause of chest pain in a young man: bronchogenic cysts and their cardiac manifestations
Authors: Magro A , Micallef J , Falzon S , Agius M , Busuttil W , Montefort S
Published: March 2010

We report a case of a 24-year-old man who presented with chest pain and electrocardiographic evidence of myocardial ischaemia. An abnormal structure located behind the heart on the urgent transthoracic echocardiogram and a computed tomography scan of the mediastinum led to prompt surgery with eventual resection of the lesion. The histology revealed fragments of connective tissue covered by squamous epithelium and ciliated epithelium, consistent with a bronchogenic cyst. The case study is accompanied by a literature review of the pathogenesis, diagnosis and management of bronchogenic cysts and their association with cardiac symptoms.
Rhabdomyolysis following co-prescription of fusidic acid and atorvastatin
Authors: Teckchandani S , Robertson S , Almond A , Donaldson K , Isles C
Published: March 2010

The placebo-corrected incidence of rhabdomyolysis in a systematic review of 20 statin trials was 1.6/100,000 per year. It is likely to be higher than this in everyday clinical practice when statins are knowingly or inadvertently co-prescribed with drugs that interfere with their metabolism. We report a case of rhabdomyolysis causing muscle weakness and prolonging an episode of dialysisdependent acute kidney injury, which occurred when fusidic acid was co-prescribed with atorvastatin. Renal function and muscle power recovered when both drugs were withdrawn. We found four other cases of rhabdomyolysis with fusidic acid and atorvastatin and three with fusidic acid and simvastatin in the literature, a review of which suggests that the risks of rhabdomyolysis vary with the extent to which an individual statin is dependent for its metabolism on the cytochrome P450 3A4 isoenzyme and the degree to which this isoenzyme’s activity is inhibited by a particular antimicrobial. Of note, the interaction between statins and fusidic acid did not feature in seven of eight recent reviews of statin toxicity. Our case report highlights the importance of close monitoring of patients on statins, especially when new drugs are started or if patients become unwell, by checking creatine kinase and liver function tests and by examining for new muscle weakness. Our review of statin–antimicrobial drug interactions suggests that fusidic acid is another CYP450 3A4 enzyme inhibitor with the potential to cause rhabdomyolysis when co-prescribed with simvastatin and atorvastatin.
Recent insights into the biology of bone turnover
Authors: Riches PL , Ralston SH
Published: March 2010

This review is based on the Croom Lecture delivered by Dr Riches at the RCPE Updates in Internal Medicine Symposium on 23 October 2009.
Plague, pox and the physician in Aberdeen, 1495–1516
Authors: Jillings K
Published: March 2010

This article discusses responses to disease in Aberdeen during a formative period in the provision of healthcare within the city. The foundation of King’s College was followed, in 1497, by the establishment of the first royally endowed university Chair of Medicine in the British Isles, and its first incumbent, James Cumming, was employed by the local government as the first city doctor in 1503. His appointment had been preceded in 1497 by another legislative innovation in Aberdeen, when its council became the first civic body in the British Isles to implement regulations against the threat of the Great Pox (usually considered to be syphilis). It had subsequently to pass measures to prevent the spread of plague to the city, and these were typical of those already imposed elsewhere in Scotland and on the continent. Their apparent success in staving off plague lasted until 1514, when the city was struck by a severe outbreak which lasted two years.
Contemporary management of coronary heart disease
Authors: Menown IBA
Published: March 2010

Coronary heart disease remains the leading cause of mortality in the UK. This review focuses on the contemporary management of patients with acute coronary syndromes and those with stable angina, including the role of primary percutaneous coronary intervention versus fibrinolytic therapy in a UK setting, current and emerging antiplatelet and anticoagulant therapies and the latest guidance on secondary prevention/lifestyle modification.
Acidophiles
Authors: Oren Aharon
Published: March 2010

Microorganisms growing in highly acidic environments (pH values below 3) are found in all three domains of life: Archaea, Bacteria and Eucarya. Such organisms thrive in acidic sulfur springs and in association with mining activities where microbial oxidation of pyrite and other reduced sulfur compounds lead to the formation of sulfuric acid. Acidophilic prokaryotes are also involved in the industrial leaching of copper and other metals from ores. Some acidophiles grow at high temperatures. Physiologically, the acidophiles are very diverse: there are aerobic and facultative anaerobic chemolithotrophs and different types of heterotrophic prokaryotes, photoautotrophic eukaryotes, predatory protozoa and others. Acidophilic microorganisms maintain their intracellular pH close to neutrality and their cytoplasmic membrane may support proton gradients up to five orders of magnitude; their membrane potential is often reversed in comparison with neutrophiles and alkaliphiles, with an intracellular positive charge.

Key concepts:

Microbial life is possible in strongly acidic environments and even at pH values below zero.

The low pH of highly acidic environments in volcanic areas and environments associated with metal ore mining is caused by the activities of acidophilic microorganisms that oxidize reduced sulfur compounds to sulfuric acid.

Acidophilic microorganisms are found in all three domains of life: Archaea, Bacteria and Eucarya.

Unicellular eukaryotic green algae such as
Dunaliella acidophila
and
Chlamydomonas acidophila
perform photosynthesis at pH values down to 0–1 and the red alga
Cyanidium caldarium
grows as a photoautotroph in acidic hot springs up to 57°C and at pH<2–4.

Some thermoacidophilic Archaea thrive at low pH up to very high temperatures.
Sulfolobus
and
Acidanus
spp. grow up to 96°C at pH 1–5;
Picrophilus oshimae
tolerates pH<0 and grows up to 65°C.

Acidophilic microorganisms keep their intracellular pH at values close to neutrality and maintain a proton gradient over their cytoplasmic membranes of up to five orders of magnitude.

In contrast to neutrophilic and alkaliphilic microorganisms that maintain an outside‐positive membrane potential, the membrane potential over the cytoplasmic membrane can be reversed, positive‐inside, in acidophilic microorganisms.

Extracellular enzymes of acidophilic microorganisms are optimally active at low pH.

Acid mine drainage is caused by the chemolithotrophic oxidation of pyrite and other reduced sulfur compounds in the ores by acidophilic prokaryotes such as
Acidithiobacillus
,
Leptospirillum
and
Ferroplasma
.

The activities of the same types of organisms that cause acid mine drainage are exploited industrially for the bioleaching of copper and other metals from ores.
Terpenoids: Lower
Authors: Phillips Michael A , Rodríguez Concepción Manuel
Published: March 2010

Lower terpenoids (monoterpenes and sesquiterpenes) are volatile components of the scents and fragrances of aromatic plants. They are frequently found in glandular hairs on leaves, in the scent glands of flowers or in specialized resin ducts in conifers. They are synthesized through stepwise condensations of isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP), the universal intermediates of isoprenoid metabolism. The precursors of monoterpenes are mainly supplied by the 2‐methylerythritol 4‐phosphate (MEP) pathway in plastids, whereas most sesquiterpenes are produced from acetate via the cytosolic mevalonate pathway. Subtle variations of basic terpene carbon skeletons have resulted in the appearance of tens of thousands of unique structures in nature, most of whose functions are currently unknown. As volatile, organic compounds, many participate in plant–plant or plant–insect chemical communications, as pollination vector attractants, feeding deterrents or in direct plant defence. Many have potent biological activities and are used in pharmaceutical and industrial applications.

Key concepts

Lower terpenoids (monoterpenes and sesquiterpenes) are volatile C
10
and C
15
compounds frequently present in floral emissions. Lower terpenoids emitted from flowers may attract symbiotic insects which assist the plant in pollination.

When some plants are attacked by insects or nematodes, they release volatile terpenoids which summon parasitic wasps who indirectly provide plants with protection by preying on their attackers.

Most plants have highly specialized structures such as trichomes where terpenoid biosynthesis and storage take place.

Lower terpenoids share a common biosynthetic origin with all other terpenoids through IPP and DMAPP, the universal C
5
metabolic precursors of all isoprenoids.

Two parallel pathways exist for the formation of IPP and DMAPP in plants, the methylerythritol phosphate pathway in plastids and the mevalonate pathway in the cytosol.

Lower terpenoids are frequently chemically modified after their initial biosynthesis to give them highly specific biological activities.

In a limited number of plant families, the monoterpene geraniol is used in the biosynthesis of monoterpene indole alkalkoids, a highly specialized family of natural products with potent pharmacological properties in humans.

C
15
sesquiterpenes are structurally diverse and are often modified through the addition of a lactone ring, which generally makes them extremely toxic to animals.
Xenopus
as an Experimental Organism
Authors: Tadjuidje Emmanuel , Heasman Janet
Published: March 2010

The South African clawed frog,

Xenopus laevis

, is used extensively as a model system to study development. It is easy to maintain a breeding colony of frogs, females can be induced to lay eggs all year round and hundreds of embryos can be generated that grow synchronously from a single fertilization. Embryos are easily amenable to microsurgery at any stage of development and adult frogs survive surgeries performed under limited aseptic conditions. The ease of injecting oligonucleotides or
messenger ribonucleic acid
(mRNA) into

Xenopus leavis

embryos has contributed to the discovery of genes with key functions in development. Another singularity of

Xenopus leavis

is the ease to manipulate its oocytes before fertilization; this has been a powerful tool to identify the function of maternally deposited mRNAs in development. Transgenic procedures are being developed using the related species

Xenopus tropicalis

and this will broaden the contribution of

Xenopus

to the understanding of early development.

Key concepts:

Xenopus laevis
is easy to raise and feed in large colonies in the laboratory.

The female
Xenopus
can be induced to spawn repeatedly at any season, making it possible to obtain embryos all year round.

Xenopus leavis
eggs are quite large, and are usually laid in large numbers that are fertilized
in vitro
.

Xenopus leavis
oocytes can easily be obtained and manipulated before fertilization, making it possible to study the function of maternally deposited mRNAs.

The
Xenopus
embryos develop outside the female and are amenable to manipulation at any stage of development.

The mechanism of tissue formation has been elucidated from research carried out on
Xenopus leavis
embryos.

Xenopus leavis
is an excellent model for studying body axis formation.

The early development of
Xenopus
is very fast, making it possible to study a full developmental programme in about three days.

The sequencing of the diploid genome, the ease of obtaining and injecting large numbers of eggs and the relatively short lifespan makes
Xenopus tropicalis
a very promising model for transgenic studies of organogenesis.

Eggs of
Xenopus leavis
provide a model of choice for studying the regulation of the cell cycle.
Immune Vasculitis
Authors: Flint Julia D , Savage Caroline OS
Published: March 2010

Vasculitis comprises a broad group of diseases characterized by inflammation and necrosis in the walls of blood vessels, resulting in narrowing or occlusion of the lumen. The conditions are usually classified according to the predominant size of the vessels involved. A wide range of immunopathological mechanisms have been implicated in the aetiology of the vasculitides and a subset of small‐vessel vasculitides are strongly associated with antineutrophil cytoplasmic antibodies (ANCA). The distribution of blood vessel involvement varies considerably, resulting in a heterogeneous clinical presentation, often involving multiple organ systems. This makes both classification and diagnosis of these diseases challenging. Clinical management is hindered by our limited understanding of the immunopathogenesis of these conditions. However, research in this area is active, many treatment trials are in progress and the morbidity and mortality has fallen in recent years.

Key concepts:

Vasculitis may be ‘idiopathic’ or ‘primary’ but it is important to rule out common mimics of vasculitis and the many underlying conditions that can induce a ‘secondary’ vasculitis.

Vasculitides are usually classified according to the predominant size of the vessels involved, but there is ongoing debate as to the most accurate and clinically useful way to classify the conditions.

Immunopathological mechanisms are diverse, with roles for both humoral and cellular immune mechanisms.

A subset of small‐vessel vasculitides are strongly associated with antineutrophil cytoplasmic antibody (ANCA) and this is often used as a biomarker to aid diagnosis.

There is strong evidence for a pathogenic role of ANCA in the ‘ANCA associated vasculitides’, but the extent of this continues to be debated.

Vasculitis is usually considered a ‘systemic’ disease with the propensity to affect blood vessels throughout the body, but individual clinical presentations may be limited to specific organ systems.

Many patients initially experience a prodrome of nonspecific symptoms such as malaise, fatigue, fever, night sweats or weight loss.

The prevalence of vasculitis is increasing. This may be due to the increased rates of diagnosis, due to clinical suspicion and use of biomarkers such as ANCA; increased survival post‐diagnosis or a true increased incidence.

Further research into the underlying pathological processes is vital to identifying potential treatment targets.

Many trials are currently in progress and will contribute to the improving rates of morbidity and mortality in systemic vasculitis.
Mastocytosis and Mast Cells
Authors: Horny Hans‐Peter
Published: March 2010

Mastocytosis is defined by abnormal accumulation of mast cells in various sites in the body. The clinical features of this chronic, multifaceted disorder originate from mast cell infiltration leading to systemic and local effects induced by numerous pharmacological mediators. Since mastocytosis is an unusual disorder and presents a multiplicity of symptoms, it is an often overlooked consideration in a differential diagnosis that includes not only asthma, chronic diarrhoea, urticaria, syncope, peptic ulceration but also various haematological neoplasms. Diagnosis of mastocytosis can be confirmed only by the pathologist using a combined immunohistochemical and molecular approach. Recognition and subtyping of its rare, life‐threatening high‐grade disease variant (i.e. mast cell leukaemia) includes not only the investigation of tissue samples (usually bone marrow) but also the blood and bone marrow smears.

Key concepts:

Mastocytosis is an unusual haematopoietic disorder derived from transformed bone marrow progenitor cells.

Clinically and histologically, mastocytosis presents an extremely broad spectrum of subvariants ranging from a benign, sometimes even regressive, cutaneous disease to the progressively fatal mast cell leukaemia.

Mastocytosis is a histological diagnosis established by the pathologist and cannot be confirmed by clinical findings alone.

Most patients with systemic mastocytosis carry the activating point mutation KITD816V in the c‐kit proto‐oncogene.

The presence of KITD816V not only explains pathophysiological disease characteristics but also enables targeting therapy using the recently developed tyrosine kinase inhibitors.

Although stated in the recent WHO classification book on haematopoietic neoplasms, mastocytosis should not be grouped among myeloproliferative neoplasms.

Mastocytosis should be considered as a separate group of disorders among haematological neoplasms.

Mastocytosis must be separated from a variety of reactive (i.e. mast cell hyperplasia) and neoplastic (i.e. basophilic leukaemia) states.
Neutrophil Functional Disorders
Authors: Rosenzweig Sergio D , Malech Harry L
Published: March 2010

The phagocytic system is one of the first lines of defence against invading microorganisms. Diseases and disorders that impair phagocyte function can lead to a profound immunodeficiency. Egression from the bone marrow, adhesion, migration, activation, phagocytosis and microorganism killing describe basic mechanisms associated to phagocytic cells. When any of these activities is affected, severe, recurrent and relapsing bacterial as well as fungal infections usually occur. Chronic granulomatous disease is a paradigmatic example of a functional disorder in phagocytic cells. This clinically and genetically heterogenous disease has served during the past 50 years as a model for understanding genotypic–phenotypic correlations of infections susceptibility in primary immunodeficiencies, the utility of anti‐infectious and cytokine prophylactic therapy, hematopoietic stem cell transplantation and gene therapy.

Key Concepts

Patients with neutrophil functional disorders usually present early in life with recurrent bacterial or fungal infections.

Certain infections, such as
Burkholderia cepacia
,
Nocardia
,
Aspergillus nidulans
or nontuberculous mycobacteria should always prompt an inquiry to the possibility of an underlying immune defect.

Specific infection locations, such as omphalitis, gingivitis or osteomyelitis, should raise the suspicion of phagocytic cell abnormalities.

Abnormal aspects of host response, such as lack of fever, local inflammation or pus, should immediately alert the clinician to the possibility of a neutrophil defect.

It is better to perform the right test once than the entire battery of immune defect tests several times. Careful consideration of the clinical and microbiologic presentation usually indicates the right path to pursue.

There is no substitute for the right drug, and that requires knowing the pathogen. Because the spectrum of infection in these diseases may range over several microbiologic kingdoms, empiric therapy is to be discouraged in favour of firm diagnoses.

Prophylactic antibiotics, antifungal agents and cytokines are highly successful in treating chronic granulomatous disease, and appear to be useful in some other immunodeficiencies as well.

A molecular diagnosis should be sought whenever possible. The expanding knowledge of genotype–phenotype relationships suggests that not all defects, even those within the same gene, are created equal.

BCG vaccination should be avoided in individuals with CGD, as well as in their newborn close relatives until the defect is ruled out. In general, attenuated viral vaccines are not contraindicated in individuals with primary neutrophil disorders, as antiviral cell‐mediated immunity is intact.
HMG
Domain Superfamily of
DNA
‐bending Proteins:
HMG
,
UBF
,
TCF
,
LEF
,
SOX
,
SRY
and Related Proteins
Authors: Koopman Peter
Published: March 2010

SRY
, the Y‐chromosome‐encoded male sex‐determining factor, is the signature member of a larger family of related transcription factors, the
SOX
proteins.
SOX
proteins are related by a DNA (
deoxyribonucleic acid
)‐binding domain known as the
HMG
(
high mobility group
) domain, which in turn unites a larger superfamily of proteins.
SRY
and
SOX
proteins are thought to regulate gene transcription through binding to specific DNA sequence motifs and causing the DNA to bend – a property of so‐called architectural transcription factors. Similarly, a related family of proteins, including
TCF‐1
(
T‐cell factor 1
),
LEF‐1
(
lymphoid enhancer factor 1
) and their relatives, regulates transcription by virtue of sequence‐specific DNA binding. A third family, the true or canonical
HMG
proteins, differs by containing multiple
HMG
domains, not binding to specific target DNA sequences, and having poorly defined roles. Here, we examine the diversity, origins, molecular functions and biological roles of the
HMG
domain superfamily.

Key Concepts:

The 80 amino acid HMG domain characterizes a superfamily of proteins found in plants and animals.

HMG domain proteins associate with DNA and usually bend it, thereby influencing transcription of genes.

The most ancient family of these proteins, represented by the canonical HMG proteins HMG‐1 and HMG‐2, have multiple HMG domains, and do not bind to any specific DNA sequences.

Genes encoding canonical HMG proteins may have evolved into two further families of genes encoding proteins that have single HMG domains and bind to specific DNA sequence motifs.

These families include SRY (the mammalian Y‐linked sex‐determining factor) and the SOX, TCF‐1 and LEF‐1 transcription factors.

Unlike canonical HMG proteins, these other HMG domain proteins have specific, important and well‐defined biological roles, particularly in embryonic development.
Nuclear Transfer from Cell Lines
Authors: Wells David N
Published: March 2010

The production of cloned animals following nuclear transfer, using somatic cells grown in culture, represents a remarkable feat of developmental biology. It demonstrates the potential of a differentiated nucleus to be reprogrammed back to an embryonic state when exposed to a suitable cytoplasmic environment, such as that of an oocyte. It involves fundamental changes to the patterns of DNA (
deoxyribonucleic acid
) methylation and chromatin modification imposed on a specialized nucleus to enable the precise temporal‐spatial sequence of gene expression necessary for normal embryogenesis. However, reprogramming is often incomplete with the development going astray, resulting in a continuum of embryo, fetal and post‐natal mortality. The majority of the clones that do survive to adulthood, and their sexually derived progeny, do, however, appear normal. This provides encouragement for the practical applications of nuclear cloning in the fields of agriculture, animal conservation and biomedicine.

Key concepts:

The cytoplasm of mature oocytes and young zygotes has the potential to reprogramme the epigenetic state and pattern of gene expression of somatic donor cells back to that of an embryo, to enable the creation of a cloned animal.

Undifferentiated embryonic blastomeres result in greater animal cloning efficiency but practically all somatic cell types are equally difficult to reprogramme.

Faulty reprogramming compromises subsequent development and is associated with serious animal welfare concerns affecting the acceptability of the current procedures in food‐producing species.

In cattle, approximately 50% of nuclear transfer embryos derived from somatic cells that are transferred to surrogate females may initiate pregnancies, but only 15% produce calves with ultimately 10% resulting in healthy adult clones. The cloning efficiencies in most other species are less than this.

Any epigenetic errors that may persist in surviving clones appear to be reset through gametogenesis and are not transmitted to progeny following sexual reproduction.

Cloning can be used in agriculture to multiply high‐value breeding animals to effectively disseminate genetic gain.

Somatic cell cloning is a valuable reproductive tool to resurrect genetically superior livestock after slaughter, accidental death, injury or disease to avoid the lost of valuable genotypes.

The milk and meat from surviving cloned livestock has similar composition to that produced from conventional livestock and is safe to consume.

Nuclear transfer is a valuable method to produce transgenic livestock from genetically modified cells for specific agricultural and biomedical applications.

The controversy over the use of human somatic cell nuclear transfer to generate patient‐specific embryonic stem cells for regenerative medicine has abated after the revelation that somatic cells can be directly reprogrammed into induced pluripotent stem cells
in vitro
, signalling the latest revolution in this field.
Nuclear Magnetic Resonance (
NMR
) Spectroscopy: Structure Determination of Proteins and Nucleic Acids
Authors: Greenbaum Nancy , Ghose Ranajeet
Published: March 2010

Nuclear magnetic resonance (NMR) spectroscopy is a powerful biophysical technique that facilitates determination of the three‐dimensional structure and interactions of proteins and nucleic acids in solution. A set of NMR experiments identifies spectral signatures corresponding to specific atoms on individual residues in the molecule and determines their order in the primary sequence. Distance and angular relationships are subsequently measured and utilized to supplement standard force‐fields used in molecular dynamics (MD)‐based protocols to obtain high‐resolution structural models. Structure determination is aided by molecular biology and biochemistry to generate samples optimally labelled with NMR‐active isotopes; by improvement in the design of NMR instrumentation to allow spectral signatures to be recorded with high sensitivity; by development of efficient techniques to manipulate nuclear spins at the quantum level; and by generation of advanced computer algorithms that allow rapid processing, manipulation and storage of large quantities of NMR data.

Key Concepts:

Solution NMR is an excellent spectroscopic technique for the determination of the three‐dimensional structure of biomolecules at near‐physiological conditions.

The abundance of chemical and structural information available from NMR spectra derives from the ability to selectively manipulate specific nuclei by customizable sequences of radio‐frequency pulses in a large static magnetic field.

NMR signals report on the variety of chemical environments experienced by nuclei in biomolecules through unique spectral signatures.

The repertoire of information‐rich NMR experiments has been expanded by the ability to enrich biomolecules with NMR‐active nuclei taking advantage of advances in molecular biology and biochemistry.

Nuclear spins in biomolecules form magnetically coupled networks, with characteristic spectral profiles that can be manipulated to extract angular, orientational and distance information for calculation of three‐dimensional structural models.
Bell's Palsy
Authors: Gilchrist James M
Published: March 2010

Bell's palsy is an idiopathic neuropathy of the facial nerve, meaning there is no known cause. It was first described in the medical literature in 1821 and is the most common cause of facial neuropathy. It usually presents as acute, weakness of one side of the entire face. This is in contrast to facial weakness from a cerebral hemisphere stroke which spares the forehead muscles of the face. Increased loudness and decreased taste on the affected side are also common, as are numbness and pain. Loss of hearing, ringing in the ears, problems with speech or swallowing or weakness elsewhere should provoke looking for another diagnosis than Bell's palsy. The chance of full recovery is excellent but the use of steroids within three days of onset, especially in patients with moderate or severe weakness, improves the chance of full recovery even further. The use of antiviral agents should probably be limited to those patients with severe weakness, or with evidence of herpes zoster infection in the ear or mouth (Ramsay Hunt syndrome).

Key concepts

Bell's palsy is the most common cause of facial neuropathy.

It is defined as idiopathic facial neuropathy.

It has as excellent prognosis, with 85% of patients having recovery by 6 months.

Steroids given within 3 days of onset improve the chance of recovery even further.

The facial nerve travels a long and bending path, which is why so many diseases can affect it.

Facial neuropathy causes weakness of the entire side of the face versus cerebral hemisphere stroke which spares the forehead muscles.

There is mounting evidence to support the hypothesis that Bell's palsy in most patients is caused by reactivation of herpes simplex virus in the geniculate ganglion.
Stanier, Roger Yate
Authors: Oren Aharon
Published: March 2010

Roger Stanier (1916–1982), a Canadian‐born microbiologist, who worked at the University of Berkeley, California and at the Institut Pasteur, Paris, and became renowned for his studies on the bacterial degradation of aromatic compounds and the taxonomy and physiology of cyanobacteria and as the author of
The Microbial World
, the major textbook of general microbiology in the 1960–1980s.
Graphite Furnace Atomic Absorption Spectrometry
Authors: Holcombe James A. , Borges Daniel L. G.
Published: March 2010

Graphite furnace atomic absorption spectrometry (GFAAS) is also known as electrothermal atomization atomic absorption spectrometry (ETAAS). It is an atomic spectroscopic technique in which a small sample is placed inside a graphite tube that is then resistively heated to accomplish sample desolvation (for liquid samples), ashing or charring (to decompose the sample and volatilize some of the matrix), and finally atomization. Typically, the light from a line source characteristic of the element being determined is passed longitudinally through the tube and the absorbance resulting from the presence of free analyte atoms in the gas phase is measured. A continuum source and high‐resolution spectrometer can accomplish a similar objective. The absorbance signal is transient in character, lasting approximately 1–5 s, and the area under this transient peak is generally used in the construction of a calibration curve. Modern instrumentation provides high levels of automation with capabilities of background correction as well as routine methods of sample analysis, for example quality assurance/quality control (QA/QC), standard additions, matrix modification, etc. Since the technique was first introduced in 1969, a lot of progress has been made in understanding the processes occurring within the graphite tube atomizer that ultimately produces the absorbance signal. An understanding of the free atoms formation process has facilitated the application of the technique to the analysis of a variety of complex samples.

Graphite furnace (also known as an electrothermal atomizer or ETA) atomic absorption is generally considered an ultratrace and microtrace analytical technique with limits of detection (LODs) in the low picogram range, precision of a few percent (relative standard deviation), and a dynamic range of about three orders of magnitude. In addition to its excellent sensitivity, it is unique in its ability to handle microsamples including aqueous solutions, viscous liquids, slurries, and even solids. In general, there is considerable literature detailing methods and procedures for the determination of a variety of analytes in complex matrices that can be used by the analyst to apply the approach to new, complex analytical needs. When used correctly, this analytical tool can provide precise, accurate analysis for a wide range of sample types.
Nuclear Magnetic Resonance and Electron Spin Resonance Spectroscopy: Introduction
Authors: Dybowski Cecil
Published: March 2010

A brief introduction to the phenomenon of magnetic resonance provides a gateway to other, more advanced discussions of the topics related to this important analytical technology.
Atmospheric‐Pressure Solid Analysis Probe (ASAP)
Authors: McEwen Charles N.
Published: March 2010

The atmospheric sample analysis probe (ASAP) is a simple but powerful direct method for the rapid analysis of a wide variety of materials. The method uses standard ion sources provided on commercial mass spectrometers without interfering with the intended operation. In addition to a fundamental description of the ASAP method, material characterization examples, including synthetic compounds, drugs, tissue, polymers, and petroleum, are presented.
Neutron Radioscopy: Industrial and Scientific Applications
Authors: Hickner Michael A. , Hussey Daniel S.
Published: March 2010

Neutron imaging is a precise measurement tool for water content in proton exchange membrane fuel cells (PEMFCs), enabling the direct measurement of the water distribution in standard, commercially viable fuel cell hardware. In the last 5–7 years, neutron imaging has proven to be an invaluable tool in fuel cell research and has provided information inaccessible by any other measurement technique. The unique aspects of imaging real fuel cells are due to the large neutron scattering cross section from hydrogenous liquids, combined with the relatively small scattering cross section from many common metals and other materials of construction. Neutron‐imaging instruments are simple in design, and high‐resolution digital neutron‐imaging detectors (down to 20 µm) are routinely available at many neutron‐imaging facilities. One drawback of neutron imaging is that a high flux neutron beamline is required, and only 6–10 facilities in the world are currently equipped to do these types of measurements. The majority of this article discusses the uses of neutron imaging to investigate water transport phenomena in PEMFCs, including optimal channel design, effects of thermal gradients, and material property effects on liquid water retention. In addition, examples are given of neutron tomography applied to the study of other hydrogen‐based energy storage systems — metal hydride storage beds and alkaline batteries.
Analytical Ultracentrifugation
Authors: Schuck Peter , Balbo Andrea , Brown Patrick H. , Zhao Huaying
Published: March 2010

Analytical ultracentrifugation is a powerful and very versatile technique for the study of particles in solution ranging from sub‐nanometers to micrometers in size. It allows the characterization of their size or size distribution, low‐resolution (hydrodynamic) shape, density, and solvation properties, and, in some cases, composition and attractive or repulsive interactions. For single‐ or multicomponent systems with reversible chemical reactions, the number and stoichiometry of complexes, the timescale of their interconversion, as well as binding constants from nanomolar to millimolar range can be determined. Analytical ultracentrifugation is based on first principles and has a long history of theoretical and practical development. This present article provides an introduction of the theoretical concept, the instrumentation, and considerations for conducting experiments and data analysis.
Quantitative Imaging of Membrane Mechanics with Molecular Resolution
Authors: Dong Mingdong , Sahin Ozgur
Published: March 2010

Atomic force microscope (AFM) is a powerful tool to study the surface morphology of biological samples. High‐resolution topographical images allow visualization of nanomaterials and characterization of nanostructures to understand functional properties in detail. However, in general, morphology is not sufficient to link structure and function of materials and biomolecules. Complementary information on optical, electronic, mechanical, thermal, chemical, and magnetic properties with nanometer‐scale spatial resolution can be extremely helpful. Recently, progress has been made in the measurement and characterization of dynamic nanomechanical properties with high spatial resolution using specially designed AFM cantilevers. High‐resolution mechanical measurements can be particularly useful in providing insights into biological membranes, because these membranes comprise biomolecules whose mechanical properties are tailored to assist their biological function. With this perspective, we review the recently developed experimental technique and its applications in quantitative imaging of membrane mechanics.
Chemometrics and Statistical Considerations in Forensic Science
Authors: Zadora Grzegorz
Published: March 2010

Questions have been raised by the police, prosecutors, and the courts concerning identification and classification of objects into certain categories and/or an association between two or more items. Most of the samples analyzed by forensic experts are very small. Therefore addressing the above‐mentioned problems requires application of various analytical methods which yield various kinds of information, i.e. about the morphology of analyzed objects and the qualitative and quantitative sample composition. When forensic analysis requires interpretation of physicochemical data, then it is common nowadays to apply statistical methods. Measurements on crime scene evidence and evidence from a suspect may be deemed to be “similar” or “very similar” and may be deemed to be “rare” or “common”. The choice of adjective may well be a personal choice and lead to a debate among experts and confusion for the people involved in the investigation. Therefore, two experts could use different adjectives having the same data when they do not use the objective method in their interpretation. This is because they could have different experiences in the field of interpretation of this particular type of evidence material (data, e.g. elemental composition of glass).

Objective assessment which takes account of the underlying variation requires the use of appropriate models. The choice of the model is, of course, a subjective one. However, once the model is chosen, the results will be determined. Different people with the same data and same model will produce the same assessment of the evidence. There is a debate here too, but this debate is about the assumptions underlying the choice of model. Are the observed variances of refractive index (RI) values equal for compared glass samples? If yes, then a Student'st‐test could be used to test the null hypothesis that ȳ1 = ȳ2. If not, then a modification of the Student'st‐test, calledWelchtest, should be used. The debate is about science, and not about the choice of adjective.

Applications of the most commonly used statistical and chemometrics methods for solving the classification and comparison problems are presented in this article. A special emphasis is made on methods based on calculation of likelihood ratio models as they seem to be the most suitable form of expression to the role of forensic expert in evaluating evidenceE(e.g. physicochemical data), in the context of the prosecution propositionH1and the defense propositionH2.
Biocatalytic Membrane Reactors
Authors: Giorno Lidietta , Drioli Enrico
Published: March 2010

Biocatalytic membrane reactors are biohybrid artificial systems where a biochemical conversion is combined with a membrane separation process. The term may indicate either that the membrane itself is biocatalytic, that is participates directly in the reaction forming the reactor's core system, or that a bioconversion step is combined with a catalytically inert membrane operation. In the latter case, the term “membrane bioreactor” is more appropriate.

With reference to the more general term “membrane reactors”, membrane bioreactors are distinguished by the fact that the chemical conversion is catalyzed by chemical catalysts of biological origin, such as enzymes and cells, instead of ordinary chemical catalysts.

Membrane science and chemical and biochemical engineering contribute to the development of these systems by designing compact, flexible, and efficient apparatuses, in which conversion and product separation from the reaction site occur simultaneously, thus enhancing yield according to Le Chatelier's principle.

Biocatalytic membrane reactors allow to carry out concentration and separation without the use of heat; they permit innovative formulation strategies; the equipments need less space, are flexible and easy to scale‐up (they are enabling technologies and respond well to the process intensification strategy); operating costs are low; energy consumed is low; products and coproducts are of high quality (which is very important for by‐product valorization, waste prevention, and minimization).

Due to the abilities of both, membrane processes and biocatalysts, to work with high selectivity and without additives, biocatalytic membrane reactors are particularly suitable for processing in the food and beverage, biotechnological, biomedical, and pharmaceutical fields, as well as in wastewater treatment.

In this work, their basic aspects and main applications in topics of current industrial interest are be discussed.
Bioelectronics
Authors: Fleming James T. , Ripp Steven
Published: March 2010

The new discipline of bioelectronics intersects the fields of biology, materials sciences, and electronics. We define bioelectronics as the interfacing of naturally occurring or synthetic biological materials with inorganic electronic materials, components or systems.

Interfacing of biomaterials and electronics has led to the development of devices that can transduce chemical signals generated by biological components into electronically readable signals or usable power. Conversely, bioelectronic components may be designed to substitute for a biological function or process, the electronic components of which are intended to facilitate the control or monitoring of that biological process. This review article first presents an overview of the three thematic elements that form the foundation of the discipline of bioelectronics, namely, biological electron transfer, the biological/electronic interface and supramolecular organization. This is followed by descriptions of the major devices and applications in the categories of biosensors, power systems and living‐cell interfacing.
Biosorption, Metals
Authors: Naja Ghinwa Melodie , Murphy Vanessa , Volesky Bohumil
Published: March 2010

Biosorption is a property of certain types of inactive, dead, microbial biomass to bind certain chemical components and thus also to concentrate heavy metals from even very dilute aqueous solutions. Certain types of biomass exhibit this property, acting just as chemical substances, as ion exchangers of biological origin. It is particularly the cell wall structure of certain algae, fungi and bacteria which was found responsible for this phenomenon. Some biomass types, serving as a basis for metal biosorption processes, can accumulate in excess of 25% of their dry weight in deposited heavy metals such as Pb, Cd, U, Cu, Zn, even Cr and others. Research on biosorption is revealing that it is sometimes a complex phenomenon where the metallic species could be deposited in the solid biosorbent through different sorption processes of ion exchange, complexation, chelation, microprecipitation, etc.

A whole new family of suitably “formulated” biosorbents can be used in the process of metal removal and detoxification of industrial metal‐bearing effluents. The sorption packed‐column configuration is the most effective mode of application for the purpose. Recovery of the deposited metals from saturated biosorbent can be accomplished because they can often be easily released from the biosorbent in a concentrated wash solution which also regenerates the biosorbent for subsequent multiple reuse. This and extremely low cost of biosorbents makes the process highly economical and competitive particularly for environmental applications in detoxifying industrial metal‐bearing effluents.
Citric Acid Processes
Authors: Kubicek Christian P. , Karaffa Levente
Published: March 2010

Citric acid is abundantly used in the food industry, but also has a number of other applications. Today it is exclusively produced by fermentation using the fungusAspergillus niger. Here, we review the current knowledge on its biochemistry and regulation of its formation, and the scientific basis for the conditions necessary to obtain high yields. Further, we explain the currently used production processes and applications.