930 research outputs found
Sex dimorphism in the association of cardiometabolic characteristics and osteophytes-defined radiographic knee osteoarthritis among obese and non-obese adults: NHANES III
SummaryObjectiveTo examine the relationship of knee osteoarthritis (OA) with cardiovascular and metabolic risk factors by obesity status and gender.MethodsData from 1,066 National Health and Nutrition Examination Survey III participants (≥60years of age) was used to examine relationships of osteophytes-defined radiographic knee OA and cardiovascular and metabolic measures. Analyses were considered among obese [body mass index (BMI)≥30kg/m2] and non-obese (BMI<30kg/m2) men and women.ResultsThe prevalence of osteophytes-defined radiographic knee OA was 34%. Leptin levels and homeostatic model assessment-insulin resistance (HOMA-IR), a proxy measure of insulin resistance, were significantly associated with knee OA; those with knee OA had 35% higher HOMA-IR values and 52% higher leptin levels compared to those without knee OA. The magnitude of the association between HOMA-IR and knee OA was strongest among men, regardless of obesity status; odds ratios (ORs) for HOMA-IR were 34% greater among non-obese men (OR=1.18) vs obese women (OR=0.88). Among obese women, a 5-μg/L higher leptin was associated with nearly 30% higher odds of having knee OA (OR=1.28). Among men, ORs for the association of leptin and knee OA were in the opposite direction.ConclusionsCardiometabolic dysfunction is related to osteophytes-defined radiographic knee OA prevalence and persists within subgroups defined by obesity status and gender. A sex dimorphism in the direction and magnitude of cardiometabolic risk factors with respect to knee OA was described including HOMA-IR being associated with OA prevalence among men while leptin levels were most important among women
Peripheral Sensitization Increases Opioid Receptor Expression And Activation By Crotalphine In Rats
Inflammation enhances the peripheral analgesic efficacy of opioid drugs, but the mechanisms involved in this phenomenon have not been fully elucidated. Crotalphine (CRP), a peptide that was first isolated from South American rattlesnake C.d. terrificus venom, induces a potent and long-lasting anti-nociceptive effect that is mediated by the activation of peripheral opioid receptors. Because the high efficacy of CRP is only observed in the presence of inflammation, we aimed to elucidate the mechanisms involved in the CRP anti-nociceptive effect induced by inflammation. Using real-time RT-PCR, western blot analysis and ELISA assays, we demonstrate that the intraplantar injection of prostaglandin E2 (PGE2) increases the mRNA and protein levels of the μ- and κ-opioid receptors in the dorsal root ganglia (DRG) and paw tissue of rats within 3 h of the injection. Using conformation state-sensitive antibodies that recognize activated opioid receptors, we show that PGE 2, alone does not increase the activation of these opioid receptors but that in the presence of PGE2, the activation of specific opioid receptors by CRP and selective μ- and κ-opioid receptor agonists (positive controls) increases. Furthermore, PGE2 down-regulated the expression and activation of the δ-opioid receptor. CRP increased the level of activated mitogen-activated protein kinases in cultured DRG neurons, and this increase was dependent on the activation of protein kinase Cζ. This CRP effect was much more prominent when the cells were pretreated with PGE 2. These results indicate that the expression and activation of peripheral opioid receptors by opioid-like drugs can be up- or down-regulated in the presence of an acute injury and that acute tissue injury enhances the efficacy of peripheral opioids. © 2014 Zambelli et al.93Stein, C., Peripheral mechanisms of opioid analgesia (1993) Anesth Analg, 76, pp. 182-191Obara, I., Parkitna, J.R., Korostynski, M., Makuch, W., Kaminska, D., Local peripheral opioid effects and expression of opioid genes in the spinal cord and dorsal root ganglia in neuropathic and inflammatory pain (2009) Pain, 141, pp. 283-291Puehler, W., Zollner, C., Brack, A., Shaqura, M.A., Krause, H., Schafer, M., Stein, C., Rapid upregulation of mu opioid receptor mRNA in dorsal root ganglia in response to peripheral inflammation depends on neuronal conduction (2004) Neuroscience, 129 (2), pp. 473-479. , DOI 10.1016/j.neuroscience.2004.06.086, PII S030645220400627XMaekawa, K., Minami, M., Masuda, T., Satoh, M., Expression of mu- and kappa-, but not delta-, opioid receptor mRNAs is enhanced in the spinal dorsal horn of the arthritic rats (1996) Pain, 64 (2), pp. 365-371. , DOI 10.1016/0304-3959(95)00132-8Cahill, C.M., Morinville, A., Hoffert, C., O'Donnell, D., Beaudet, A., Up-regulation and trafficking of delta opioid receptor in a model of chronic inflammation: Implications for pain control (2003) Pain, 101 (1-2), pp. 199-208. , DOI 10.1016/S0304-3959(02)00333-0Hassan, A.H.S., Ableitner, A., Stein, C., Herz, A., Inflammation of the rat paw enhances axonal transport of opioid receptors in the sciatic nerve and increases their density in the inflamed tissue (1993) Neuroscience, 55 (1), pp. 185-195. , DOI 10.1016/0306-4522(93)90465-RZollner, C., Shaqura, M.A., Bopaiah, C.P., Mousa, S., Stein, C., Schafer, M., Painful inflammation-induced increase in mu-opioid receptor binding and G-protein coupling in primary afferent neurons (2003) Molecular Pharmacology, 64 (2), pp. 202-210. , DOI 10.1124/mol.64.2.202Shaqura, M.A., Zollner, C., Mousa, S.A., Stein, C., Schafer, M., Characterization of mu Opioid Receptor Binding and G Protein Coupling in Rat Hypothalamus, Spinal Cord, and Primary Afferent Neurons during Inflammatory Pain (2004) Journal of Pharmacology and Experimental Therapeutics, 308 (2), pp. 712-718. , DOI 10.1124/jpet.103.057257Antonijevic, I., Mousa, S.A., Schafer, M., Stein, C., Perineurial defect and peripheral opioid analgesia in inflammation (1995) J Neurosci, 15, pp. 165-172Mousa, S.A., Zhang, Q., Sitte, N., Ji, R.-R., Stein, C., beta-endorphin-containing memory-cells and mu-opioid receptors undergo transport to peripheral inflamed tissue (2001) Journal of Neuroimmunology, 115 (1-2), pp. 71-78. , DOI 10.1016/S0165-5728(01)00271-5, PII S0165572801002715Konno, K., Picolo, G., Gutierrez, V.P., Brigatte, P., Zambelli, V.O., Crotalphine, a novel potent analgesic peptide from the venom of the South American rattlesnake Crotalus durissus terrificus (2008) PeptidesGutierrez, V.P., Zambelli, V.O., Picolo, G., Chacur, M., Sampaio, S.C., The peripheral L-arginine-nitric oxide-cyclic GMP pathway and ATP-sensitive K channels are involved in the antinociceptive effect of crotalphine on neuropathic pain in rats Behav Pharmacol, 23, pp. 14-24Gutierrez, V.P., Konno, K., Chacur, M., Sampaio, S.C., Picolo, G., Crotalphine induces potent antinociception in neuropathic pain by acting at peripheral opioid receptors (2008) Eur J Pharmacol, 594, pp. 84-92Granados-Soto, V., Rufino, M.D.O., Gomes, L.L.D., Ferreira, S.H., Evidence for the involvement of the nitric oxide-cGMP pathway in the antinociception of morphine in the formalin tests (1997) European Journal of Pharmacology, 340 (2-3), pp. 177-180. , DOI 10.1016/S0014-2999(97)01399-X, PII S001429999701399XSachs, D., Cunha, F.Q., Ferreira, S.H., Peripheral analgesic blockade of hypernociception: Activation of arginine/NO/cGMP/protein kinase G/ATP-sensitive K+ channel pathway (2004) Proceedings of the National Academy of Sciences of the United States of America, 101 (10), pp. 3680-3685. , DOI 10.1073/pnas.0308382101Pacheco, D.F., Reis, G.M.L., Francischi, J.N., Castro, M.S.A., Perez, A.C., Duarte, I.D.G., delta-Opioid receptor agonist SNC80 elicits peripheral antinociception via delta1 and delta2 receptors and activation of the L-arginine/nitric oxide/cyclic GMP pathway (2005) Life Sciences, 78 (1), pp. 54-60. , DOI 10.1016/j.lfs.2005.04.032, PII S0024320505006697Amarante, L.H., Duarte, I.D.G., The kappa-opioid agonist (+/-)-bremazocine elicits peripheral antinociception by activation of the L-arginine/nitric oxide/cyclic GMP pathway (2002) European Journal of Pharmacology, 454 (1), pp. 19-23. , DOI 10.1016/S0014-2999(02)02275-6, PII S0014299902022756Cunha, T.M., Roman-Campos, D., Lotufo, C.M., Duarte, H.L., Souza, G.R., Morphine peripheral analgesia depends on activation of the PI3Kgamma/AKT/nNOS/NO/KATP signaling pathway Proc Natl Acad Sci U S A, 107, pp. 4442-4447Law, B.K., Waltner-Law, M.E., Entingh, A.J., Chytil, A., Aakre, M.E., Norgaard, P., Moses, H.L., Salicylate-induced growth arrest is associated with inhibition of p70s6k and down-regulation of c-Myc, cyclin D1, cyclin A, and proliferating cell nuclear antigen (2000) Journal of Biological Chemistry, 275 (49), pp. 38261-38267. , DOI 10.1074/jbc.M005545200Belcheva, M.M., Clark, A.L., Haas, P.D., Serna, J.S., Hahn, J.W., Kiss, A., Coscia, C.J., Mu and kappa opioid receptors activate ERK/MAPK via different protein kinase C isoforms and secondary messengers in astrocytes (2005) Journal of Biological Chemistry, 280 (30), pp. 27662-27669. , DOI 10.1074/jbc.M502593200Connor, M., Christie, M.J., Opioid receptor signalling mechanisms (1999) Clinical and Experimental Pharmacology and Physiology, 26 (7), pp. 493-499. , DOI 10.1046/j.1440-1681.1999.03049.xZimmermann, M., Ethical guidelines for investigations of experimental pain in conscious animals (1983) Pain, 16, pp. 109-110Picolo, G., Giorgi, R., Bernardi, M.M., Cury, Y., The antinociceptive effect of Crotalus durissus terrificus snake venom is mainly due to a supraspinally integrated response (1998) Toxicon, 36 (1), pp. 223-227. , DOI 10.1016/S0041-0101(97)00048-2, PII S0041010197000482Von Banchet, G.S., Scholze, A., Schaible, H.-G., Prostaglandin E2 increases the expression of the neurokinin1 receptor in adult sensory neurones in culture: A novel role of prostaglandins (2003) British Journal of Pharmacology, 139 (3), pp. 672-680Picolo, G., Giorgi, R., Cury, Y., delta-Opioid receptors and nitric oxide mediate the analgesic effect of Crotalus durissus terrificus snake venom (2000) European Journal of Pharmacology, 391 (1-2), pp. 55-62. , DOI 10.1016/S0014-2999(99)00934-6, PII S0014299999009346Gendron, L., Pintar, J.E., Chavkin, C., Essential role of mu opioid receptor in the regulation of delta opioid receptor-mediated antihyperalgesia (2007) Neuroscience, 150 (4), pp. 807-817. , DOI 10.1016/j.neuroscience.2007.09.060, PII S0306452207012365Lomas, L.M., Barrett, A.C., Terner, J.M., Lysle, D.T., Picker, M.J., Sex differences in the potency of kappa opioids and mixed-action opioids administered systemically and at the site of inflammation against capsaicin-induced hyperalgesia in rats (2007) Psychopharmacology, 191 (2), pp. 273-285. , DOI 10.1007/s00213-006-0663-1Ji, Y., Murphy, A.Z., Traub, R.J., Estrogen modulation of morphine analgesia of visceral pain in female rats is supraspinally and peripherally mediated (2007) J Pain, 8, pp. 494-502. , JPicolo, G., Cury, Y., Peripheral neuronal nitric oxide synthase activity mediates the antinociceptive effect of Crotalus durissus terrificus snake venom, a delta- and kappa-opioid receptor agonist (2004) Life Sciences, 75 (5), pp. 559-573. , DOI 10.1016/S0024-3205(04)00292-9, PII S0024320504002929Randall, L.O., Selitto, J.J., A method for measurement of analgesia activity on inflamed tissue (1957) Arch Inst Pharmacodyn, 111, pp. 209-219Bradford, M.M., A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding (1976) Anal Biochem, 72, pp. 248-254Gupta, A., Decaillot, F.M., Gomes, I., Tkalych, O., Heimann, A.S., Conformation state sensitive antibodies to G-protein coupled receptors (2006) J Biol ChemCunha, T.M., Souza, G.R., Domingues, A.C., Carreira, E.U., Lotufo, C.M., Stimulation of peripheral Kappa opioid receptors inhibits inflammatory hyperalgesia via activation of the PI3Kgamma/AKT/nNOS/NO signaling pathway Mol Pain, 8, p. 10Bruchas, M.R., Chavkin, C., Kinase cascades and ligand-directed signaling at the kappa opioid receptor Psychopharmacology, 210, pp. 137-147. , BerlBerra, E., Diaz-Meco, M.T., Dominguez, I., Municio, M.M., Sanz, L., Lozano, J., Chapkin, R.S., Moscat, J., Protein kinase C zeta isoform is critical for mitogenic signal transduction (1993) Cell, 74 (3), pp. 555-563Kwong, K., Lee, L.-Y., Prostaglandin E2 potentiates a TTX-resistant sodium current in rat capsaicin-sensitive vagal pulmonary sensory neurones (2005) Journal of Physiology, 564 (2), pp. 437-450. , DOI 10.1113/jphysiol.2004.078725Southall, M.D., Vasko, M.R., Prostaglandin receptor subtypes, EP3C and EP4, mediate the prostaglandin E2-induced cAMP production and sensitization of sensory neurons (2001) J Biol Chem, 276, pp. 16083-16091Ferreira, S.H., Lorenzetti, B.B., Prostaglandin hyperalgesia, IV: A metabolic process (1981) Prostaglandins, 21, pp. 789-792Stein, C., Millan, M.J., Shippenberg, T.S., Peter, K., Herz, A., Peripheral opioid receptors mediating antinociception in inflammation. Evidence for involvement of mu, delta and kappa receptors (1989) Journal of Pharmacology and Experimental Therapeutics, 248 (3), pp. 1269-1275Mousa, S.A., Machelska, H., Schafer, M., Stein, C., Immunohistochemical localization of endomorphin-1 and endomorphin-2 in immune cells and spinal cord in a model of inflammatory pain (2002) Journal of Neuroimmunology, 126 (1-2), pp. 5-15. , DOI 10.1016/S0165-5728(02)00049-8, PII S0165572802000498Furst, S., Riba, P., Friedmann, T., Timar, J., Al-Khrasani, M., Obara, I., Makuch, W., Schmidhammer, H., Peripheral versus central antinociceptive actions of 6-amino acid-substituted derivatives of 14-O-methyloxymorphone in acute and inflammatory pain in the rat (2005) Journal of Pharmacology and Experimental Therapeutics, 312 (2), pp. 609-618. , DOI 10.1124/jpet.104.075176Nunez, S., Lee, J.-S., Zhang, Y., Bai, G., Ro, J.Y., Role of peripheral mu-opioid receptors in inflammatory orofacial muscle pain (2007) Neuroscience, 146 (3), pp. 1346-1354. , DOI 10.1016/j.neuroscience.2007.02.024, PII S030645220700173XSchafer, M., Imai, Y., Uhl, G.R., Stein, C., Inflammation enhances peripheral mu-opioid receptor-mediated analgesia, but not mu-opioid receptor transcription in dorsal root ganglia (1995) Eur J Pharmacol, 279, pp. 165-169Zhou, L., Zhang, Q., Stein, C., Schafer, M., Contribution of opioid receptors on primary afferent versus sympathetic neurons to peripheral opioid analgesia (1998) Journal of Pharmacology and Experimental Therapeutics, 286 (2), pp. 1000-1006Lecat, S., Bucher, B., Mely, Y., Galzi, J.-L., Mutations in the extracellular amino-terminal domain of the NK2 neurokinin receptor abolish cAMP signaling but preserve intracellular calcium responses (2002) Journal of Biological Chemistry, 277 (44), pp. 42034-42048. , DOI 10.1074/jbc.M203606200Decaillot, F.M., Befort, K., Filliol, D., Yue, S.Y., Walker, P., Kieffer, B.L., Opioid receptor random mutagenesis reveals a mechanism for G protein-coupled receptor activation (2003) Nature Structural Biology, 10 (8), pp. 629-636. , DOI 10.1038/nsb950Selley, D.E., Breivogel, C.S., Childers, S.R., Modification of G protein-coupled functions by low-pH pretreatment of membranes from NG108-15 cells: Increase in opioid agonist efficacy by decreased inactivation of G proteins (1993) Molecular Pharmacology, 44 (4), pp. 731-741Belcheva, M.M., Vogel, Z., Ignatova, E., Avidor-Reiss, T., Zippel, R., Levy, R., Young, E.C., Coscia, C.J., Opioid modulation of extracellular signal-regulated protein kinase activity is ras-dependent and involves G(betagamma) subunits (1998) Journal of Neurochemistry, 70 (2), pp. 635-645Bohn, L.M., Belcheva, M.M., Coscia, C.J., Mitogenic signaling via endogenous kappa-opioid receptors in C6 glioma cells: Evidence for the involvement of protein kinase C and the mitogen- activated protein kinase signaling cascade (2000) Journal of Neurochemistry, 74 (2), pp. 564-573. , DOI 10.1046/j.1471-4159.2000.740564.xBruchas, M.R., Macey, T.A., Lowe, J.D., Chavkin, C., Kappa opioid receptor activation of p38 MAPK is GRK3- and arrestin-dependent in neurons and astrocytes (2006) Journal of Biological Chemistry, 281 (26), pp. 18081-18089. , http://www.jbc.org/cgi/reprint/281/26/18081, DOI 10.1074/jbc.M513640200Sweatt, J.D., Mitogen-activated protein kinases in synaptic plasticity and memory (2004) Curr Opin Neurobiol, 14, pp. 311-317Thomas, G.M., Huganir, R.L., MAPK cascade signalling and synaptic plasticity (2004) Nature Reviews Neuroscience, 5 (3), pp. 173-183Carlezon Jr., W.A., Duman, R.S., Nestler, E.J., The many faces of CREB (2005) Trends in Neurosciences, 28 (8), pp. 436-445. , DOI 10.1016/j.tins.2005.06.005, PII S016622360500158XBruchas, M.R., Xu, M., Chavkin, C., Repeated swim stress induces kappa opioid-mediated activation of extracellular signal-regulated kinase 1/2 (2008) Neuroreport, 19, pp. 1417-1422Kreibich, A.S., Blendy, J.A., cAMP response element-binding protein is required for stress but not cocaine-induced reinstatement (2004) Journal of Neuroscience, 24 (30), pp. 6686-6692. , DOI 10.1523/JNEUROSCI.1706-04.2004Bruchas, M.R., Yang, T., Schreiber, S., DeFino, M., Kwan, S.C., Li, S., Chavkin, C., Long-acting kappa opioid antagonists disrupt receptor signaling and produce noncompetitive effects by activating c-Jun N-terminal kinase (2007) Journal of Biological Chemistry, 282 (41), pp. 29803-29811. , http://www.jbc.org/cgi/reprint/282/41/29803, DOI 10.1074/jbc.M705540200Melief, E.J., Miyatake, M., Bruchas, M.R., Chavkin, C., Ligand-directed c-Jun N-terminal kinase activation disrupts opioid receptor signaling (2010) Proc Natl Acad Sci U S A, 107, pp. 11608-11613Velazquez, K.T., Mohammad, H., Sweitzer, S.M., Protein kinase C in pain: Involvement of multiple isoforms (2007) Pharmacological Research, 55 (6), pp. 578-589. , DOI 10.1016/j.phrs.2007.04.006, PII S104366180700084
Welfare of horses from Mexico and the United States of America transported for slaughter in Mexico: Fitness profiles for transport and pre-slaughter logistics
Every year thousands of horses from Mexico and the United States of America (USA) are transported to slaughter in Mexico, but little is known about their welfare or pre-slaughter logistics. In this study, we recorded the origin, sex, age and condition of horses (121 journeys, 2648 animals) upon arrival to an abattoir in northern Mexico, including transport details. Horse welfare was measured indirectly via individual scores for body condition, coat quality, lameness, ocular and nasal discharge, as well as reactivity to a chute restraint test, all performed shortly after unloading. The average journey duration was 9.69 (±7.6) hours for horses from Mexico and 16.77 (±4.51) hours for horses from the USA (77 % of all journeys). The prevalence of ocular discharge, nasal discharge, skin wounds, lameness and diarrhoea, were 23 %, 12 %, 11 %, 9 %, 1 % (respectively) of all the horses observed, with no significant differences between Mexican and American horses (P = 0.05). During the chute test the American horses were calmer than the Mexican ones (P < 0.001), who were more restless and aggressive (P = 0.001). Likewise, vocalizations in their three variants during the restraint, neigh/whinny (P = 0.018), nicker (P < 0.001), and snort (P = 0.018), were more common in horses from Mexico. In order to help characterize fitness for transport, a two-step cluster analysis was applied using the welfare indicators, suggesting the existence of four clusters (C) evaluated on arrival at the abattoir (from good to very poor fitness): good (profile C4, n = 769, 29.1 %), average (profile C1, n = 799 horses, 30.2 %), poor (profile C3, n = 586, 22.1 %) and very poor (profile C2, n = 494, 18.6 %). In fact, the C4 best welfare group had 0% lame, 0% nasal discharge, 16.4 % ocular discharge, 7.9 % skin wounds. Instead, the C2 poorest welfare group had 45.8 % lame, 61.1 % nasal discharge, 42.8 % ocular discharge, and 19.9 % skin wounds. Results show potential for using nasal discharge, lameness and ocular discharge as key indicators of horse fitness and welfare on abattoir. The study provides detailed scientific data to help establish strategies regarding optimal days of recovery post-transport and fattening for homogenization of weights between animals of different origins, logistic planning, and optimization of logistic resources to minimize the biological cost of long-distance transport
The transfer of fibres in the carding machine
The problem of understanding the transfer of fibres between carding-machine surfaces is addressed by considering the movement of a single fibre in an airflow. The structure of the aerodynamic flow field predicts how and when fibres migrate between the different process surfaces. In the case of a revolving-flats carding machine the theory predicts a “strong” aerodynamic mechanism between taker-in and cylinder and a “weak” mechanism between cylinder and removal cylinder resulting in effective transfer in the first case and a more limited transfer in the second
Ultrasound imaging for the rheumatologist XXVI. Sonographic assessment of the knee in patients with psoriatic arthritis
Objective. To investigate the prevalence and severity of sonographic-detected abnormalities in,knee osteoarthritis (OA) and to correlate ultrasound (US) findings with clinical data. Methods. Outpatients with chronic, painful knee OA according to the ACR criteria were consecutively recruited and underwent clinical and US examinations. An expert rheumatologist recorded the presence of knee joint pain, swelling and tenderness, patient's global assessment of knee pain using visual analogue scale (VAS), and Lequesne Index of severity for knee OA. A second rheumatologist, blinded to the clinical data, performed the knee US examination using a Logiq9 machine equipped with a 12MHz linear probe and registering the presence of joint effusion, synovial proliferation, power Doppler (PD) signal, Baker's cyst, osteophytes and femoral cartilage abnormalities. Results. One hundred and sixty-four knees of 82 patients (53 women, 29 men) were studied; mean age was 63.2 +/- 8.1 SD years, mean disease duration was 4.3 +/- 5.6 SD years. All patients complained of at least one knee joint pain during physical activity. Mean patient's VAS for knee pain was 48.4 +/- 19.9 SD mm, mean Lequesne Index was 8.2 +/- 4.4 SD. Knee swelling was present in 39% of the patients and tenderness was found in 65.8%. US showed: joint effusion in 43.3% of the patients, synovial proliferation in 22.1%, PD signal in 2.9%, Baker's cysts in 6.6%, cartilage abnormalities in 79%, osteophytes in 100%. In all patients US findings were present at least at the level of one knee. Statistically significant correlations were demonstrated between a composite inflammatory score and both VAS (p=0.004) and Lequesne Index (p < 0.0001). Conclusions. This US study showed both inflammatory abnormalities and structural damage lesions in knee OA. Interestingly, statistically significant correlations were demonstrated between US inflammatory findings and the main clinical tests for OA, confirming that sonography has a relevant role in the global evaluation of patients with knee OA
The biology and behavior of the longhorned beetle, Dectes texanus on sunflower and soybean
The biology and behavior of the longhorned beetle Dectes texanus LeConte (Coleoptera: Cerambycidae) was studied on two host plants that suffer economic losses from this pest; sunflower, Helianthus annuus, and soybean, Glycines max. Reciprocal crosses of D. texanus collected from the two plants all produced viable progeny, indicating that conspecific insects attack both crops. Pupae from soybean stalks weighed about 40% less than those from sunflower, and adults fed on soybean lived a mean of 23 days, compared to a mean of 53 days (males) and 76 days (females) for those fed sunflower. A female's larval host plant had no effect on her tendency to ovipuncture plants of either type in a greenhouse trial. A field-tested population collected exclusively from sunflower contained three types of females in similar proportions: those that laid eggs only on sunflower, those that laid only on soybean, and those that laid equally on both host plants. Females in field trials fed more on the plant they had fed on in the laboratory, but soybean-fed females fed more on soybean than did sunflower-fed females. Females fed soybean also made more ovipunctures on soybean plants in field trials than sunflower-fed females, but their responses to sunflower plants were similar. Females displayed higher total ovipositional activity when they encountered sunflower first in the field, and lower total activity when they encountered soybean first. Feeding scores were significantly correlated with ovipunctures and eggs on both plant types. We conclude that sunflower is the preferred host plant, although females will accept soybean when it is the only available food. The results suggest that D. texanus is still in the initial stages of a host range expansion with female host selection behavior demonstrating both genetic influences and phenotypic flexibility. Sunflower represents a nutritionally superior, ancestral host plant and relatively high fitness costs are still associated with utilization of the novel host plant, soybean, costs that may be offset by benefits such as reduced intraspecific competition. These potential benefits and their consequent implications for D. texanus host range evolution are hypothesized and discussed
The Global Forest Transition as a Human Affair
Forests across the world stand at a crossroads where climate and land-use changes are shaping their future. Despite demonstrations of political will and global efforts, forest loss, fragmentation, and degradation continue unabated. No clear evidence exists to suggest that these initiatives are working. A key reason for this apparent ineffectiveness could lie in the failure to recognize the agency of all stakeholders involved. Landscapes do not happen. We shape them. Forest transitions are social and behavioral before they are ecological. Decision makers need to integrate better representations of people’s agency in their mental models. A possible pathway to overcome this barrier involves eliciting mental models behind policy decisions to allow better representation of human agency, changing perspectives to better understand divergent points of view, and refining strategies through explicit theories of change. Games can help decision makers in all of these tasks
Methods to estimate aboveground wood productivity from long-term forest inventory plots
Forest inventory plots are widely used to estimate biomass carbon storage and its change over time. While there has been much debate and exploration of the analytical methods for calculating biomass, the methods used to determine rates of wood production have not been evaluated to the same degree. This affects assessment of ecosystem fluxes and may have wider implications if inventory data are used to parameterise biospheric models, or scaled to large areas in assessments of carbon sequestration. Here we use a dataset of 35 long-term Amazonian forest inventory plots to test different methods of calculating wood production rates. These address potential biases associated with three issues that routinely impact the interpretation of tree measurement data: (1) changes in the point of measurement (POM) of stem diameter as trees grow over time; (2) unequal length of time between censuses; and (3) the treatment of trees that pass the minimum diameter threshold (“recruits”). We derive corrections that control for changing POM height, that account for the unobserved growth of trees that die within census intervals, and that explore different assumptions regarding the growth of recruits during the previous census interval. For our dataset we find that annual aboveground coarse wood production (AGWP; in Mg ha−1 year−1 of dry matter) is underestimated on average by 9.2% if corrections are not made to control for changes in POM height. Failure to control for the length of sampling intervals results in a mean underestimation of 2.7% in annual AGWP in our plots for a mean interval length of 3.6 years. Different methods for treating recruits result in mean differences of up to 8.1% in AGWP. In general, the greater the length of time a plot is sampled for and the greater the time elapsed between censuses, the greater the tendency to underestimate wood production. We recommend that POM changes, census interval length, and the contribution of recruits should all be accounted for when estimating productivity rates, and suggest methods for doing this.European UnionUK Natural Environment Research CouncilGordon and Betty Moore FoundationCASE sponsorship from UNEP-WCMCRoyal Society University Research FellowshipERC Advanced Grant “Tropical Forests in the Changing Earth System”Royal Society Wolfson Research Merit Awar
Demonstration of the temporal matter-wave Talbot effect for trapped matter waves
We demonstrate the temporal Talbot effect for trapped matter waves using
ultracold atoms in an optical lattice. We investigate the phase evolution of an
array of essentially non-interacting matter waves and observe matter-wave
collapse and revival in the form of a Talbot interference pattern. By using
long expansion times, we image momentum space with sub-recoil resolution,
allowing us to observe fractional Talbot fringes up to 10th order.Comment: 17 pages, 7 figure
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