Dinitrogen (N2) fixation rates were measured during early spring across the different provinces of Mediterranean Sea surface waters. N2 fixation rates, measured using N2 enriched seawater, were lowest in the eastern basin and increased westward with a maximum at the Strait of Gibraltar (0.10 to 2.35 nmol N L−1 d−1, respectively). These rates were 3–7 fold higher than N2 fixation rates measured ...

The effect of the refractive index of the substrate together with the incident polarization on the optimization of sawtooth surface-relief gratings (SRGs) is investigated. The global optimum diffraction efficiencies of the -1st forward-diffracted order of sawtooth SRGs are 63.3% occurring at n2=1.47 for TE polarization and 73.8% occurring at n2=2.88 for TM polarization. Incident TE polarization...

Abstract. Let X1, ..., Xn1 be a random sample from a population with mean μ1 and variance σ 2 1 , and Y1, ..., Yn2 be a random sample from another population with mean μ2 and variance σ 2 2 independent of {Xi, 1 ≤ i ≤ n1}. Consider the two sample t-statistic T = X̄−Ȳ −(μ1−μ2) √ s1/n1+s 2 2/n2 . This paper shows that lnP (T ≥ x) ∼ −x2/2 for any x := x(n1, n2) satisfying x → ∞, x = o(n1 + n2) as n...

Soil denitrification is considered the most unconstrained process in the global N cycle due to uncertain in situ N2 flux measurements, particularly in natural and semi-natural terrestrial ecosystems. N tracer approaches can provide in situ measurements of both N2 and N2O simultaneously, but their use has been limited to fertilized agroecosystems due to the need for large N additions in order to...

The hemoglobin receptor IsdB rapidly acquires heme from methemoglobin (metHb) in the heme acquisition pathway of Staphylococcus aureus. IsdB consists of N-terminal segment (NS), NEAT1 (N1), middle (MD), and heme binding NEAT2 (N2) domains, and C-terminal segment (CS). This study aims to elucidate the roles of these domains or segments in the metHb/IsdB reaction. Deletion of CS does not alter th...