Survey Results from Participants of a Short Course for Dairy Herdsmen

A survey was conducted by University of California Cooperative Extension of past attendees of a dairy herdsman short course. The purpose was to determine to what degree course participants were applying course material to their respective position as dairy herdsmen. Overall, 41% of the attendees indicated that they had begun to apply information from the short course on the dairy farm for which they worked. Hispanic attendees appreciated simultaneous translations of presentations. Results from this survey demonstrate the need for a dairy herdsman short course in order for dairy employees to improve their practical skills in dairy herd management

Hole Spin Coherence in a Ge/Si Heterostructure Nanowire

Relaxation and dephasing of hole spins are measured in a gate-defined Ge/Si nanowire double quantum dot using a fast pulsed-gate method and dispersive readout. An inhomogeneous dephasing time $T_2^* \sim 0.18~\mathrm{\mu s}$ exceeds corresponding measurements in III-V semiconductors by more than an order of magnitude, as expected for predominately nuclear-spin-free materials. Dephasing is observed to be exponential in time, indicating the presence of a broadband noise source, rather than Gaussian, previously seen in systems with nuclear-spin-dominated dephasing.Comment: 15 pages, 4 figure

Antilocalization of Coulomb Blockade in a Ge-Si Nanowire

The distribution of Coulomb blockade peak heights as a function of magnetic field is investigated experimentally in a Ge-Si nanowire quantum dot. Strong spin-orbit coupling in this hole-gas system leads to antilocalization of Coulomb blockade peaks, consistent with theory. In particular, the peak height distribution has its maximum away from zero at zero magnetic field, with an average that decreases with increasing field. Magnetoconductance in the open-wire regime places a bound on the spin-orbit length ($l_{so}$ < 20 nm), consistent with values extracted in the Coulomb blockade regime ($l_{so}$ < 25 nm).Comment: Supplementary Information available at http://bit.ly/19pMpd

Scanning Probe Microscopy for Nanoscale Characterization of Electrical and Magnetic Properties

Atomic force microscopy (AFM) is a nanoscale scanning probe microscopy (SPM) characterization technique useful for obtaining topographical maps of surfaces and their associated nanomechanical properties. Complementary SPM modes such as Kelvin probe force microscopy (KPFM) and magnetic force microscopy (MFM) can simultaneously elucidate the electrical and magnetic properties of materials with nanoscale resolution, thereby expanding AFM’s utility. KPFM measures the Volta potential difference between a conductive AFM probe and the sample surface, which can be related back to the work function of the material and correlated with co-localized elemental mapping via energy dispersive spectroscopy (EDS). This can be useful for understanding and predicting initiation and propagation of galvanic corrosion in metal alloys. MFM employs a magnetized AFM probe tip to detect magnetic interactions between the sample and the tip, thereby mapping out the magnetic structure of the sample surface. Here we present KPFM studies of case-hardened stainless steels engineered for bearing applications in high performance jet engines destined for operation in corrosive marine environments. MFM studies of Ni-Mn-Ga, a magnetic shape memory alloy, connect experimental data with computational modeling to understand the growth of twins in response to bending. Together, these studies highlight the widespread applicability of AFM, KPFM, MFM, and other SPM techniques for illuminating nanoscale structure-property relationships in material systems

Radiotherapy biobanking : current landscape, opportunities, challenges, and future aspirations

This work was supported by the National Cancer Research Institute (NCRI) Clinical and Translational Radiotherapy Research Working Group (CTRad), which was established in 2009 by six of the NCRI's funding partners. We gratefully acknowledge Carolyn Chan and Julie Stock (NCRI) for their assistance in collecting the responses to the questionnaire sent to CTRad membership. Open Access via the Wiley OA AgreementPeer reviewedPublisher PD

Screening and evaluation of antiparasitic and in vitro anticancer activities of Panamanian endophytic fungi

Many compounds produced by fungi have relevant pharmaceutical applications. The purpose of this study was to collect and isolate endophytic fungi from different regions of Panama and then to test their potential therapeutic activities against Leishmania donovani, Plasmodium falciparum, and Trypanosoma cruzi as well as their anticancer activities in MCF-7 cells. Of the 25 fungal isolates obtained, ten of them had good anti-parasitic potential, showing selective activity against L. donovani; four had significant anti-malarial activity; and three inhibited the growth of T. cruzi. Anticancer activity was demonstrated in four isolates. Of the active isolates, Edenia sp. strain F0755, Xylaria sp. strain F1220, Aspergillus sp. strain F1544, Mycoleptodiscus sp. strain F0194, Phomopsis sp. strain F1566, Pycnoporus sp. strain F0305, and Diaporthe sp. strain F1647 showed the most promise based on their selective bioactivity and lack of toxicity in the assays.Many compounds produced by fungi have relevant pharmaceutical applications. The purpose of this study was to collect and isolate endophytic fungi from different regions of Panama and then to test their potential therapeutic activities against Leishmania donovani, Plasmodium falciparum, and Trypanosoma cruzi as well as their anticancer activities in MCF-7 cells. Of the 25 fungal isolates obtained, ten of them had good anti-parasitic potential, showing selective activity against L. donovani; four had significant anti-malarial activity; and three inhibited the growth of T. cruzi. Anticancer activity was demonstrated in four isolates. Of the active isolates, Edenia sp. strain F0755, Xylaria sp. strain F1220, Aspergillus sp. strain F1544, Mycoleptodiscus sp. strain F0194, Phomopsis sp. strain F1566, Pycnoporus sp. strain F0305, and Diaporthe sp. strain F1647 showed the most promise based on their selective bioactivity and lack of toxicity in the assays

Microthyriaceae sp., an endophytic fungus

In screening for natural products with antiparasitic activity, an endophytic fungus, strain F2611, isolated from above-ground tissue of the tropical grass Paspalum conjugatum (Poaceae) in Panama, was chosen for bioactive principle elucidation. Cultivation on malt extract agar (MEA) followed by bioassayguided chromatographic fractionation of the extract led to the isolation of the new polyketide integrasone B (1) and two known mycotoxins, sterigmatocystin (2) and secosterigmatocystin (3). Sterigmatocystin (2) was found to be the main antiparasitic compound in the fermentation extract of this fungus, possessing potent and selective antiparasitic activity against Trypanosoma cruzi, the cause of Chagas disease, with an IC50 value of 0 13 lmol l 1. Compounds 2 and 3 showed high cytotoxicity against Vero cells (IC50 of 0 06 and 0 97 lmol l 1, respectively). The new natural product integrasone B (1), which was co-purified from the active fractions, constitutes the second report of a natural product possessing an epoxyquinone with a lactone ring and exhibited no significant biological activity. Strain F2611 represents a previously undescribed taxon within the Microthyriaceae (Dothideomycetes, AscomycotaIn screening for natural products with antiparasitic activity, an endophytic fungus, strain F2611, isolated from above-ground tissue of the tropical grass Paspalum conjugatum (Poaceae) in Panama, was chosen for bioactive principle elucidation. Cultivation on malt extract agar (MEA) followed by bioassayguided chromatographic fractionation of the extract led to the isolation of the new polyketide integrasone B (1) and two known mycotoxins, sterigmatocystin (2) and secosterigmatocystin (3). Sterigmatocystin (2) was found to be the main antiparasitic compound in the fermentation extract of this fungus, possessing potent and selective antiparasitic activity against Trypanosoma cruzi, the cause of Chagas disease, with an IC50 value of 0 13 lmol l 1. Compounds 2 and 3 showed high cytotoxicity against Vero cells (IC50 of 0 06 and 0 97 lmol l 1, respectively). The new natural product integrasone B (1), which was co-purified from the active fractions, constitutes the second report of a natural product possessing an epoxyquinone with a lactone ring and exhibited no significant biological activity. Strain F2611 represents a previously undescribed taxon within the Microthyriaceae (Dothideomycetes, AscomycotaLaboratory of Tropical Bioorganic Chemistry, Faculty of Natural Exact Sciences and Technology, University of Panama, Panama City, Republic of Panama Smithsonian Tropical Research Institute, Balboa, Panama City, Republic of Panama Centro de Biodiversidade, Gen omica Integrativa e Funcional (BioFIG), Universidade de Lisboa, Faculdade de Ci^encias, Edif ıcio ICAT/TecLabs, Campus da FCUL, Campo Grande, Lisboa, Portugal Institute for Advanced Scientific Investigation and High Technology Services, National Secretariat of Science, Technology, and Innovation, City of Knowledge, Panama City, Republic of Panama School of Plant Sciences, The University of Arizona, Tucson, AZ, USA Department of Biology, University of Utah, Salt Lake City, UT, USA Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography and Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA, US

Screening and evaluation of antiparasitic and in vitro anticancer activities of Panamanian endophytic fungi

Parasitic infections are major causes of human chronic diseases in most countries of the tropics. The parasites include protozoa and helminths, infect billions of people, and the resulting diseases cause debilitating injuries such as blind ness and disfigurement, or death in millions of people. According to World Health Organization (WHO) estimates, 25% of the human population is infected with parasitic worms. However, attempts to develop vaccines against these pathogens have been frustrated by the difficulty of cultivating the parasites in the laboratory, the complexity of their multicellular organization and—in many species—their multistage development, in addition to their impressive antigenic variability [http://www.who.int/vaccine_research/diseases/ soa_parasitic/en/index.html]. Malaria is the most dangerous parasitic disease, as evidenced by the high rates of complications and mortality caused by the most fatal species, Plasmodium falciparum [15]. Chagas disease, or American trypanosomiasis, is a potentially life-threatening two-phase illness caused by the protozoan Trypanosoma cruzi. The acute phase persists for about two months after infection; symptoms are absent or mild and can include fever, headache, enlarged lymph glands, pallor, muscle pain, difficulty in breathing, swelling, and abdominal or chest pain. In the chronic phase, the parasites reside mainly in the heart and digestive muscle, resulting in cardiac disorders in up to 30% of patients and digestive, neurological, or mixed pathologies in up to 10%. Eventually, the infection can lead to sudden death or heart failure, caused by progressive destruction of cardiac muscle [10,15]. Leishmaniasis, a worldwide disease, is caused by several species of the flagellated protozoan parasite Leishmania. In its more severe forms, the disease causes serious disfigurement and may be fatal. The WHO estimates a worldwide prevalence of leishmaniasis of approximately 12 million cases, with an annual mortality of about 60,000 and approximately 350 million people at risk. The expansion of leishmaniasis and the alarming rise in the number of cases has been attributed to environmental changes, such as deforestation, dam construction, new irrigation schemes, and the migration of non-immune individuals to endemic areas [10,15]. At the same time, the frequency of drug-resistant parasites has greatly increased and most treatments involve highly toxic drugs. In addition, the chemotherapeutic agents used in patients with these diseases have lacked effectiveness. Thus, there is an urgent need to search for novel drugs from previously unexplored sources, including natural products, to combat the global health problems posed by parasitic infections. Cancer is another major cause of mortality worldwide; in 2008, it accounted for 7.6 million deaths. According to WHO forecasts, an increase to 11 million deaths annually is expected by 2030. The prevalence is higher in low and middle-income countries. As a part of the on-going research activities, the Panamanian International Cooperative Biodiversity Group (ICBG) [17] recently decided to explore endophytic fungi as a source of molecules with antiparasitic and anticancer bioactivities [18,21,22]. Within the ICBG program, we have assayed the antiparasitic and in vitro anticancer activities of 25 isolates, while also analyzing the effect of the culture medium on the production of secondary metabolites by Panamanian endophytic fungi. The results of these studies are reported and discussed hereinParasitic infections are major causes of human chronic diseases in most countries of the tropics. The parasites include protozoa and helminths, infect billions of people, and the resulting diseases cause debilitating injuries such as blind ness and disfigurement, or death in millions of people. According to World Health Organization (WHO) estimates, 25% of the human population is infected with parasitic worms. However, attempts to develop vaccines against these pathogens have been frustrated by the difficulty of cultivating the parasites in the laboratory, the complexity of their multicellular organization and—in many species—their multistage development, in addition to their impressive antigenic variability [http://www.who.int/vaccine_research/diseases/ soa_parasitic/en/index.html]. Malaria is the most dangerous parasitic disease, as evidenced by the high rates of complications and mortality caused by the most fatal species, Plasmodium falciparum [15]. Chagas disease, or American trypanosomiasis, is a potentially life-threatening two-phase illness caused by the protozoan Trypanosoma cruzi. The acute phase persists for about two months after infection; symptoms are absent or mild and can include fever, headache, enlarged lymph glands, pallor, muscle pain, difficulty in breathing, swelling, and abdominal or chest pain. In the chronic phase, the parasites reside mainly in the heart and digestive muscle, resulting in cardiac disorders in up to 30% of patients and digestive, neurological, or mixed pathologies in up to 10%. Eventually, the infection can lead to sudden death or heart failure, caused by progressive destruction of cardiac muscle [10,15]. Leishmaniasis, a worldwide disease, is caused by several species of the flagellated protozoan parasite Leishmania. In its more severe forms, the disease causes serious disfigurement and may be fatal. The WHO estimates a worldwide prevalence of leishmaniasis of approximately 12 million cases, with an annual mortality of about 60,000 and approximately 350 million people at risk. The expansion of leishmaniasis and the alarming rise in the number of cases has been attributed to environmental changes, such as deforestation, dam construction, new irrigation schemes, and the migration of non-immune individuals to endemic areas [10,15]. At the same time, the frequency of drug-resistant parasites has greatly increased and most treatments involve highly toxic drugs. In addition, the chemotherapeutic agents used in patients with these diseases have lacked effectiveness. Thus, there is an urgent need to search for novel drugs from previously unexplored sources, including natural products, to combat the global health problems posed by parasitic infections. Cancer is another major cause of mortality worldwide; in 2008, it accounted for 7.6 million deaths. According to WHO forecasts, an increase to 11 million deaths annually is expected by 2030. The prevalence is higher in low and middle-income countries. As a part of the on-going research activities, the Panamanian International Cooperative Biodiversity Group (ICBG) [17] recently decided to explore endophytic fungi as a source of molecules with antiparasitic and anticancer bioactivities [18,21,22]. Within the ICBG program, we have assayed the antiparasitic and in vitro anticancer activities of 25 isolates, while also analyzing the effect of the culture medium on the production of secondary metabolites by Panamanian endophytic fungi. The results of these studies are reported and discussed herei