Achieving landscape-scale deer management for biodiversity conservation: The need to consider sources and sinks

Hyper-herbivory following predator removal is a global issue. Across North America and Europe, increasing deer numbers are affecting biodiversity and human epidemiology, but effectiveness of deer management in heterogeneous landscapes remains poorly understood. In forest habitats in Europe, deer numbers are rarely assessed and management is mainly based on impacts. Even where managed areas achieve stable or improving impact levels, the extent to which they act as sinks or persist as sources exporting deer to the wider landscape remains unknown. We present a framework to quantify effectiveness of deer management at the landscape scale. Applied across 234 km2 of Eastern England, we assessed management of invasive Reeve’s muntjac (Muntiacus reevesi) and native roe (Capreolus capreolus), measuring deer density (using thermal imaging distance transects 780 km/year), fertility, neonatal survival, and culling to quantify source-sink dynamics over 2008–2010. Despite management that removed 23–40% of the annual population, 1,287 (95% CI: 289–2,680) muntjac and 585 (454–1,533) roe deer dispersed annually into the wider landscape, consistent with their ongoing range expansion. For roe deer, culled individuals comprised fewer young deer than predicted by a Leslie matrix model assuming a closed population, consistent with agedependent emigration. In this landscape, for roe and muntjac, an annual cull of at least 60% and 53%, respectively, is required to offset annual production. Failure to quantify deer numbers and productivity has allowed high density populations to persist as regional sources contributing to range expansion, despite deliberative management programs, and without recognition by managers who considered numbers and impacts to be stable. Reversing an unfavorable condition of woodland biodiversity requires appropriate culls across large contiguous areas, supported by knowledge of deer numbers and fertility

Role of Myeloid-Derived Suppressor Cells in tumor-associated pregnancy

Cancer progression is dependent, in part, on interactions between tumor cells and the host microenvironment. During pregnancy, physiological changes occur that include inflammation and reduced immunity, both of which can promote tumor growth. Accordingly, tumors are observed to be more aggressive and to have greater proclivity toward metastasis during pregnancy. In this work, myeloid-derived suppressor cells (MDSC), a population of heterogeneous and pluripotent cells that can down-regulate immune responses during pathological conditions, were studied in the context of mouse and human gestation. The gene expression profile of mouse MDSC has been shown to differ in pregnant and virgin mice, and the profile in pregnant animals bears similarity to that of MDSC associated with the tumor microenvironment. Common induced genes include Fibronectin1 and Olfactomedin4, which are known to be involved in extracellular matrix remodeling and tissue permissiveness to tumor cells implantation. Our observations suggest that mouse MDSC may represent a shared regulatory mechanism of tissue permissiveness that occurs during the physiological state of gestation and tumor growth. Pregnancy-associated changes in immunosuppressive myeloid cell activity have also been studied in humans. We show that CD33+ myeloid cells isolated from PBMC (peripheral blood mononuclear cells) of pregnant women are more strongly immunosuppressive on T cells than CD33+ cells removed from non-pregnant subjects. During murine gestation, decreased natural killer (NK) cell activity is responsible, at least in part, for the increase in experimental metastasis. However, although peripheral blood NK cell numbers and cytotoxicity were slightly reduced in pregnant women, neither appeared to be regulated by CD33+ cells. Nevertheless, based on its observed suppression of T cell responses, the CD33+ PBMC subset appears to be an appropriate myeloid cell population to study in order to elucidate mechanisms of immune regulation that occur during human pregnancy. Our findings regarding the immunosuppressive function of CD33+cells and the role of NK cells during human pregnancy are consistent with the notion that changes in the function of the immune system participate in the constitution of a permissive soil for tumour progression

Combination Antihypertensive Therapy: Does It Have a Role in Rational Therapy?

The pharmacological treatment of hypertension allows one to reduce substantially the risk of developing a cardiovascular complication. It appears more and more important to bring blood pressure to normal values in order to get the maximal benefit from antihypertensive therapy. Blood pressure lowering drugs make it possible to control blood pressure in about half of the patients when administered as monotherapy. The fraction of patients with a normal blood pressure can be markedly increased by combining drugs acting by different mechanisms. Low doses of antihypertensive agents are generally enough when coadministered. This helps to keep the incidence of side effects minimal and facilitates the patient's compliance with long-term treatment. Low-dose, fixed-dose combination therapy may therefore represent a valuable option not only to treat hypertensive patients unresponsive to drugs given as monotherapy, but also to initiate the treatment. Am J Hypertens 1997;10:131S-137S ©1997 American Journal of Hypertension, Lt

P-210: Beta-blockade with nebivolol enhances the acetylcholine-induced vasodilation in the cutaneaous vascular bed of normotensive volunteers

This study was undertaken to assess whether the beta1-adrenoceptor blocker nebivolol(N) increases the vasodilatory response to acetylcholine(Ach) when administered orally to healthy subjects. To this end 12 volunteers were randomly allocated to a 8-day treatment with nebivolol (n), 5 mg once a day, and atenolol(A),50 mg once a day, according to a cross-over design, with a 1 week wash-out period between the two treatment phases. The forearm skin blood flow(SBF) response to Ach applied by iontophoresis was determined using a laser-Doppler scanner imaging system before(T0) and 3 hours(T3) after N or A dosing, both on the first (Day 1) and the last day (Day 8) of treatment. The following Table shows the responses of SBF (perfusion units) (means±SD; *p<0.05 versus T0): Day 1 Day 8 T0 T3 T0 T3 Nebivolol 98±93 441±109* 393±110 426±105* Atenolol 396±97 410±99 380±109 394±98 Iontophoresis of 0.09% NaCl had no effect on SBF. These data indicate that nebivolol (administered at a dose commonly used in clinical practice), but not atenolol, enhances in humans the vasorelaxant activity of Ach in the skin vascular bed, which is compatible with a facilitation by this beta-blocker of the endothelium-dependent vasodilatio