The determination of the minimal inhibitory concentration (MIC) was conducted by broth microdilution, with the microplates sealed and incubated at 35 °C for 24–72 h. The MIC was defined as the smallest concentration able to inhibit the click here growth of microorganisms. The result was expressed as the average of three separate tests (Souza, Stamford, Lima, & Trajano, 2007). The antibacterial and antifungal activities were interpreted based on the following parameters: from no growth to 0.5 mg mL−1, excellent/optimal activity; from no growth to 0.6–1.5 mg mL−1, moderate activity; from no growth to over 1.6 mg mL−1, low activity

(Houghton, Howes, Lee, & Steventon, 2007). Chloramphenicol (0.1 mg mL−1) and nystatin (100 IU mL−1) were used for the negative control, and for the positive control, the inoculation was performed using only DMSO. CT99021 order The analyses were made in triplicate and the results expressed as the average ± standard deviation. The analyses of correlations (p ⩽ 0.05) between the pollen, phenolic compounds and ABTS were investigated by multivariate statistical analysis in PAST 2.17. A total of 22 pollen types, belonging to 16 different botanical families, were identified in the honey samples (Table 1). Five pollen types that were lacking an established botanical affinity were named “Undetermined”. The Fabaceae family stood out in the pollen spectrum with six recognised pollen types. The high

pollen diversity found in the honeys reflects the flora diversity filipin of Amazonas state, a feature that favours the production of honeys with different characteristics. The pollen type Clidemia from the Melastomataceae family was identified in six of the seven samples analysed. It is present in both state regions in which the honey samples were collected, with the smallest occurrence (1.34%) in CAD3 and the largest occurrence (90.96%) in CAD4 ( Table 1). These data show that the bees M. s. merrilae collect material from species of the Melastomataceae family; however, plants from this family are often polliniferous and have a low nectar production. Clidemia and Miconia (Melastomataceae)

constitute important protein sources for Meliponini, and their pollen grains are harvested by several stingless bee species in the Amazon. Moreover, Melastomataceae is typically found in vegetable formations in the Amazon rain forest. Its flowers show poricidal anthers, and they are therefore visited primarily by bees able to vibrate the anthers in a phenomenon known as buzz pollination, which is characteristic of bees such as Bombus and Xylocopa ( Renner, 1989). The honey samples collected in SAD1, CAD2 and CAD4, representing the two state regions analysed had Clidemia pollen in quantities greater than 65% of the overall identified pollen. In the analysed honey samples, no secondary pollen types were found, and the percentages of the important minor pollen and minor pollen were low.

In this patient granulomas were not found on pathology and presence of individual interstitial giant cells and focal bronchiolization was noted with recommendation to consider HP. Diagnosis to be considered is HP maybe due to history of mycoplasma pneumonia with dry coughs. The second case is

a 30-year-old male farmer with history of exposure to toxins and well drilling in the oil industry who presents with progressive dyspnea and right-sided pleuritic chest pain for the past year. Patient’s functional class has varied between I and IV. He notes worsening of symptoms in the sitting position. He has had weakness and fevers with chills in the afternoons with nightly sweats for the past year. He has been hospitalized with diagnosis of pneumonia, but never fully recovered after discharge and continued to have dry coughs which were worse on exertion. Osimertinib in vivo He has had decreased appetite with weight loss of 15 kg in the past 8 months. He denies cough or sputum and has been referred by specialist from the city of Ahvaz where he was worked up with chest X-ray showing interstitial infiltrate in base of two lungs, restrictive spirometry, normal bronchoscopy and smear for BK. He

has continued to have exert ional dyspnea and as a result was referred to this center. Medications on admission were prednisolone started at 60 mg/d and tapered over 6 months to the current Dichloromethane dehalogenase dose of 5 mg/d, theophyline 200 mg qd and omeprazole. He is nonsmoker and does not drink alcohol or abuse VE-822 chemical structure substance.

He has history of pancreatic cancer in his father. On physical exam vital signs are BP = 100/60, PR = 100, RR = 16 and oral T = 37.2 °C. The patient was a young man alert and oriented providing history. He had no jugular venous distension or head and neck lympadenopathy. Cardiac exam was normal with heart sounds S1 and S2 present with no murmurs, rubs or gallops auscultated. Lung exam showed decreased breath sounds in the right lung base and hyper resonance on percussion. Abdominal exam showed epigastric tenderness with no organomegally. There was no clubbing, cyanosis or edema noted. Neurology exam was normal. HRCT of lung showed uniform ground glass opacities in dependent part of lower lung zone, mosaic pattern of attenuation in the rest of lung parenchyma and reported as nonspecific consistent with BOOP, PCP or early NSIP. Bronchoscopy was done which showed bronchial narrowing due to external compression in lingula. Bronchoalveolar lavage showed neutrophilia (17%) with 256 lymphocyte count and CD4/CD8 ratio of 3.8 and was negative for malignancy. Results of open lung biopsy were reported as consistent with NSIP pattern either idiopathic or secondary to another process. Considering occupation of farming, it was recommended that chronic HP be investigated.

In acidic

solutions, the current decreased with a decrease in the pH solution. This behaviour can be attributed to the protonation of complexation sites present in the modified material, preventing the Cu(II) accumulation at the CPE-CTS. Thus, acetate buffer solution (0.1 mol L−1, Ulixertinib pH 6.0) was selected as the supporting electrolyte in further studies. The effect of the CTS percentage (10–30% w/w) in the CPE on the voltammetric response of the sensor was evaluated. The maximum anodic current peak was obtained with 15% (w/w) of CTS in the paste and a 5.0 × 10−5 mol L−1 Cu(II) solution. For lower Cu(II) concentrations, a decrease in the current was observed, which can be attributed to the low amount of CTS available for the Cu(II) complexation. On the other hand, the current decrease observed when the CTS concentration in the paste was higher than 15% can be explained by the decrease in the electronic conductivity of the modified CPE, since CTS shows poor conductivity which can not be supplied by the low concentration of graphite.

Consequently, the composition of 15:20:65% (w/w/w) CTS:Nujol:graphite powder, respectively, www.selleckchem.com/products/AC-220.html was used in the construction of the CPE-CTS. In stripping voltammetry the analyte pre-concentration from the solution to the electrode surface is a critical step. In most cases, a pre-concentration potential (Epc) is applied for a preset time (tpc) and both of these parameters exert a strong influence on the electrode voltammetric response. The effect of the Epc from −0.1 to −0.7 V and a pre-concentration step carried out at open circuit potential on the anodic current peak obtained by cyclic voltammetry employing the CPE-CTS in a 5.0 × 10−5 mol L−1 Cu(II) solution were evaluated. At open circuit potential the pre-concentration was poor. Better results were obtained at controlled-potential, particularly at −0.4 V, which was the potential chosen to be employed in the subsequent tests. Another important parameter that must be precisely controlled in the experiments is the pre-concentration time. Increased tpc resulted in increasing anodic currents. A linear relationship was

observed over 90 s, but with increasing wideness in the anodic current peak, causing a Non-specific serine/threonine protein kinase considerable loss of resolution. Therefore, the tpc that provided the best relationship between voltammetric profile and current magnitude was 180 s, which was used in further experiments. Ensuring a clean electrode after the stripping is important in order to achieve reproducible results. Thus, the conditioning potential (0.1–0.7 V) and time (0–120 s) of the anodic current supplied by the CPE-CTS were studied. The cleaning step removes adsorbed impurities and copper that remain on the electrode surface after the stripping. The studies showed that a potential of 0.5 V applied for 30 s after each experiment is sufficient to clean the electrode surface. These conditioning parameters were therefore used in all subsequent experiments.

Aliquots of 0.8 mL of 0.2 mM DPPH (Sigma-Aldrich) methanolic solution

were mixed click here with 0.2 mL of the extract. The mixture was shaken vigorously and then left to stand for 30 minutes under low light. The absorbance was measured at 520 nm using a spectrophotometer (UV-1650PC; Shimadzu, Kyoto, Japan). The percentage of inhibition of activity was calculated as: equation(1) (A0−A1)/A0×100(A0−A1)/A0×100where A0 is the absorbance without the sample and A1 is the absorbance with the sample. Sample concentrations providing 50% inhibition (IC50) were calculated from a graph of inhibition percentage versus extract concentration. All samples were analyzed in triplicate. The 2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical cation scavenging activity of the 80% ethanol extract on the heated ginseng was measured according to the method of Re et al [14], with some modifications. The ABTS radical cation was generated by adding 7 mM ABTS to 2.45 mM potassium Bortezomib solubility dmso persulfate solution and leaving the mixture to stand overnight in the dark at room temperature. The ABTS radical cation solution was diluted with distilled water to obtain an absorbance of 1.4–1.5 at 735 nm. A 1 mL aliquot of diluted ABTS radical cation solution was added to 50 μL of the extract, ascorbic acid standard

solution, or distilled water. The absorbance at 735 nm was determined using a spectrophotometer (UV-1650PC; Shimadzu) after 60 minutes. The ascorbic acid equivalent antioxidant activity (AEAC) was calculated as: equation(2) (ΔA/ΔAAA)×CAA(ΔA/ΔAAA)×CAAwhere ΔA is the change in absorbance after the addition of the extract, ΔAAA is the change in absorbance after

the addition of ascorbic acid standard solution, and CAA is the concentration of the ascorbic acid standard solution. The ABTS radical cation scavenging activity was expressed as the AEAC in milligrams of ascorbic acid equivalents (mg AA eq). All samples were analyzed in triplicate. The reducing power of the extracts was determined using the method described by Kong et al [15]. To each extract Dichloromethane dehalogenase sample of 250 μL, 250 μL of 0.2M phosphate buffer at a pH of 6.6 and 250 μL of 1% (w/v) K3Fe(CN)6 were added. The mixture was incubated at 50°C for 20 minutes, after which 10% (w/v) trichloroacetic acid (250 μL) was added to it. The resulting mixture was centrifuged at 2,220 × g for 10 minutes. The upper 500-μL layer was mixed with 500 μL of deionized water and 100 μL of 0.1% (w/v) ferric chloride, and the absorbance was measured at 700 nm using a spectrophotometer. A higher absorbance indicated a higher reducing power. Results are reported as mean ± standard deviation. The significance of differences among treatment means was determined using a one-way analysis of variance with SPSS version 12 (SPSS Inc., Chicago, IL, USA) and a significance level of p < 0.05.

Khwaja and Roy [4] have given nutrient ranges in ginseng based on extensive sampling of growers’ fields. Minimum and maximum B concentrations in leaves of 2–4-yr-old plants were: 5 μg/g, deficient; 5–15 μg/g, low; 16–50 μg/g, sufficient; 51–100 μg/g, high; and >100 μg/g, excessive. Konsler and Shelton [5] and Konsler et al [6] described the effect of lime and phosphorus on the growth, nutrient status, and ginsenoside content of the ginseng root. Ginseng production in Ontario, Canada, the major center for American ginseng culture,

is on sandy and sandy-loam soil with low organic matter content, along the north shore of Lake PD-1/PD-L1 inhibitor 2 Erie [7]. In general, these soils are low in B for production of many crops [8] and [9]. Previously, we reported that the rusty root of ginseng and associated internal browning of roots grown in the above-mentioned soils may be linked to B deficiency [10]. B is required by plants only in small amounts, therefore, overapplication Crizotinib nmr to crops can occur easily.

Oliver [11] recommended that to maintain adequate soil levels of B for ginseng cultivation, 1–2 kg/ha should be applied when soil tests show ≤0.5 μg/mL. B is taken up through the plant roots as boric acid and transported with the transpiration flow. In most plants, B is highly immobile [12], being restricted to the transpiration stream. Accumulation of B can occur at the end of the transpiration stream in the leaves [13]. Manifestation of B toxicity shows as damage to tissues where it accumulates. Although B toxicity is crop-specific, Idelalisib research buy it generally leads to chlorosis and necrosis starting at the edges of mature leaves [12] and [13]. This development of necrotic areas can reduce leaf photosynthetic potential, cause a reduction of photosynthetic supply to the

developing root system, the economic part of the ginseng plant, and restrict activity in the meristematic tissues. It is unclear why B is toxic to plants, or why some plants can tolerate B and evade toxicity [13]. Reid et al [14] concluded that, at high B concentrations, many cellular processes are retarded and these are often made worse in light by photoxidative stress. Ginseng is a perennial plant requiring about 4 yr from seeding to root harvest, therefore, we examined the possibility of using radish as a time-saving model system in our B nutritional studies. Radish requires 3–6 wk from seeding to root harvest and B deficiency induces root splitting and brown heart disorder [15], similar to brown heart in ginseng [10]. Also, B toxicity in radish reduces root growth [16] and [17]. Lack of definitive data on B nutrition of American ginseng, the supposed deleterious effects on the leaves, roots, and meristematic regions, and an application of a high concentration of B to commercial ginseng plantings prompted this investigation.

These data suggest that timber production is the most frequent function for smallholder-priority tree species, and the commercial value of timber planting in smallholdings pan-tropically

is confirmed by incomplete economic data for the sector (e.g., teak [Tectona grandis; Roshetko et al., 2013] and acacia [Acacia mangium and Acacia auriculiformis; Fisher and Gordon, 2007] wood production by Indonesian and Vietnamese smallholders, respectively). After timber, our survey of the AFTD suggests medicine and then fuel are the next most important functions. Most tree species listed by the AFTD are indicated to have a range of possible uses in agroforestry systems. Multiple uses illustrate the flexibility in the products and services that agroforestry trees can provide,

which can help support diverse livelihoods selleck products and promote production-system resilience HDAC inhibitor (Garrity, 2004). The environmental services provided by agroforests in parallel (such as erosion control and shade/shelter, as listed in Table 1, as well as global services such as carbon sequestration; Roshetko et al., 2007) with their production functions can be supported by ‘payments for environmental services’ (PES) (Roshetko et al., 2008). Experience shows, however, that more important in determining the tree planting and retention behaviour of farmers is the products they receive directly from trees, not PES (Roshetko et al., 2007). A recent example of the successful adoption of improved agroforestry technologies in Africa is for soil fertility replenishment

(Place et al., 2011). The planting of nitrogen-fixing Aprepitant ‘fertiliser trees’ in the south of the continent to substitute for (or enhance) mineral fertiliser application has resulted in increased staple crops yields, more stable crop production in drought years and improved crop rain-use efficiency (Sileshi et al., 2008 and Sileshi et al., 2012). A recent project in Malawi, for example, encouraged more than 180,000 farmers to plant fertiliser trees, leading to improvements in maize yields, more food secure months per year and greater dietary diversity (CIE, 2011). Further approaches to improve soil fertility in Africa include farmer-managed natural regeneration (FMNR) of faidherbia (Faidherbia albida) and other leguminous trees, which since 1985 in Niger alone has led to the ‘regreening’ of approximately 5 million hectares ( Sendzimir et al., 2011). FMNR in the Sahel region has resulted in increases in sorghum and millet yields, with greater dietary diversity and improvements in household incomes also observed in some locations ( Bayala et al., 2011 and Place and Binam, 2013). Unlike the wide-scale planting of exotic trees in improved fallows, FMNR is based explicitly on indigenous species, which may better support biodiversity and other associated environmental services ( Haglund et al., 2011).

However, 20(S)-Rh1 reached its maximum at 4 h and decreased gradually, possibly by further dehydration at C-20 position to yield Rh4 or Rk3. The content of Rh4 was gradually increased even after 12 h ( Fig. 5). Quantitative results are summarized in Table 1. Two unknown

peaks were identified in HPLC chromatogram (Fig. 3). The contents of these unknown peaks were calculated by comparing their ELSD responses to those of MR2 and Rb1, respectively, as ELSD response is almost VE-821 order proportional to the amount of analyte. The total content of saponin in VG prior to steaming was 212.4 mg/g, which decreased to 144.2 mg/g after 20 h steaming (Table 1). Fig. 6 summarizes the change in antiproliferative activity of processed VG on A549 lung cancer cell line. The antiproliferative effect was rapidly increased upon steaming and reached its maximum at 12 h. It is noteworthy that the antiproliferative activity seems to have a close relationship with the sum of the content of PPD-type less polar ginsenosides Rg3, Rg5, and Rk1 (Fig. 7), which is in accordance with the report that these less polar ginsenosides have stronger antiproliferative activity than their polar analogs [13], [19], [22] and [23]. Even though antiproliferative activity and the content of PPD-type less polar ginsenoside

seem to have a close relationship, there might be other unknown factors that affect the activity as the curves of 0.5 mg/mL in Figs. 6, 7 are not all the http://www.selleckchem.com/products/cilengitide-emd-121974-nsc-707544.html same. PPT-type less polar ginsenosides Rh1, Rk3, and Pyruvate dehydrogenase lipoamide kinase isozyme 1 Rk4 were also increased by steaming; however, they have little antiproliferative effect [23]. Concentration of 3 mg/mL was too high for the test of antiproliferative activity as raw sample itself inhibited cell proliferation by 70% as shown in Fig. 6. DPPH radical scavenging activity, by contrast, continuously increased until 20 h (Fig. 8). This can be attributed by the fact that two activities are arisen from different

chemical constituents. Antiproliferative activity arises from ginsenosides whereas radical scavenging activity is arisen mainly from phenolic compounds and Maillard reaction products [24]. Steaming of Vietnamese ginseng at 120°C changed its saponin constituents and biological activities remarkably. Polar PPD and PPT ginsenosides transformed to their less polar analogs rapidly, whereas ocotillol saponins were stable upon steaming process. Antioxidant and antiproliferative activities are greatly increased by steaming. It seems that the antiproliferative activity of processed VG is closely related to the content of ginsenoside Rg3, Rg5, and Rk1. All contributing authors declare no conflicts of interest. This work was supported by the grant from the Ministry of Education, Science, and Technology of Korea (No. 2012048796), Rural Development Administration of Korea (No. PJ008202022013), and Ministry of Science and Technology of The Socialist Republic of Vietnam (No.

These A/Cal DI particles can transmit the antiviral 244 DI virus to other cells in the respiratory tract, and progressively increase the number of cells that are able to resist infection through the

presence of DI RNA. Treatment with DI virus did not adversely affect the clearance of virus infectivity, and DI RNA was cleared from nasal secretions at a similar rate. The role of interferon VX-770 mouse in protection of ferrets from A/Cal was not investigated. Studies in mice showed that active DI virus given intranasally in the absence of infectious virus stimulates production of interferon type I in the lung, and that the UV-inactivated DI virus did not stimulate detectable interferon type I in the lung. However, use of interferon receptor knock-out mice showed that interferon was not required for protection against type A influenza virus (Dimmock et al., 2008), but did protect mice from pneumonia virus of mice and an influenza B virus (Easton et al., 2011 and Scott et al., 2011b). UV-inactivated DI virus did not protect, and thus does not induce interferon type I. Oseltamivir

treatment was also beneficial although it did not cause any significant decrease in weight loss or respiratory disease when compared to the infected animals that Alpelisib mouse were not given any other treatment. Oseltamivir reduced virus load on day 2, but the virus load in oseltamivir-treated animals was more than 100-fold

greater than the virus control on day 6. This differential appears consistent with a viral rebound observed following the cessation of oseltamivir treatment in people infected with pandemic 2009 virus (Lee et al., 2011). We also examined virus from oseltamivir-treated ferrets on day 6 by sequencing for the H275Y mutation that is associated with resistance to oseltamivir (Ives et al., 2002) but this mutation was not found (unpublished data). The H275Y mutation was also absent from rebound virus in the oseltamivir-treated human cohort (Lee et al., 2011). We surmise that the rebound virus may result from the release of progeny virus that had before been bound to cell receptors because of the inhibition of viral neuraminidase activity by oseltamivir. All many ferrets developed A/Cal-specific, serum HI antibody, but there was significantly less in the oseltamivir-treated infected group than in the DI virus treated infected group. In addition to the signs and symptoms described above ferrets were monitored in the morning and the afternoon for loss of appetite, appearance of diarrhoea, and reduction in activity. None of these was seen in any group. We conclude that treatment of ferrets with 244 DI virus ameliorates clinical disease and virus load resulting from infection with pandemic A/California/04/09 (H1N1) more effectively than did treatment with oseltamivir.

, 2008). Land cover/use layers from 1895, 1975, 1989, 2000, and 2010 were used at the largest scale of analysis, which encompassed Pool 6 and its floodplains, covering an area of 72.2 km2. The

1895 dataset from the Mississippi River Commission (USACE, 1895) was digitized by the USGS. The remaining land cover/use data sets were digitized by the USGS, with polygon interpretations based on photo overlays, EROS satellite imagery, aerial imagery, and color infrared imagery (http://www.umesc.usgs.gov/rivers/upper_mississippi/reach1/pool_6/p6_gis_data.html). For the 1931 Brown Survey (USACE, 1931), land/water features were digitized for this project. Details of the coding of these layers are in Freyer (2013). In this analysis, land contiguous with uplands Selleck Volasertib or levees was not distinguished from mid-channel islands. Within the P6 and using the same data sources, a Pool 6 Managed Channel (P6MC) area focuses analyses on the active channels, covering an area of 29.9 km2. Areas outside of the levees, railroads, and managed areas adjacent to the active channel such as docks and ports were excluded. The second scale of analysis encompassed 3.65 km2 of the lower portion of Pool 6 (LP6) from Lock and Dam

6 upstream to river mile 716.5. In addition to the above datasets, historical aerial photos (Table 1) were scanned R428 clinical trial and imported to ArcGIS. Methods for georeferencing and registering imagery were adopted from previous studies (Zanoni et al., 2008). Each of the images

was georeferenced from previously orthorectified Digital Orthophoto Quadrangles and color infrared mosaic images. Ten to twenty ground control points (GCPs) were identified on each aerial photo. GCPs were bridges, structures associated Lock and Dam 6, and road intersections adjacent to the river. The maximum acceptable RMS error value for this study was <1, giving ground measurements an average error of ±1 m. Final rectification employed a cubic convolution image resample (Zanoni et al., 2008), and emergent areas were digitized. RMS values represent only some of the errors that should be considered in GIS analysis of aerial photography; Hughes et al. (2006) and Day et al. (2013) provide more comprehensive treatments of this topic. Selecting only photos during that corresponded with normal pool elevations for post-dam datasets (643–645.35 ft) (Table 1) also minimized error. The LP6 area was divided into 10 sectors with boundaries chosen to minimize division of 1895 and 2010 contiguous land areas into multiple sectors (Fig. 5). Sectors 1 and 10 consist of land attached to the river banks, while sectors 2–9 consist of mid-channel islands. Four sets of bathymetric data surround an island group known unofficially as the Mobile Islands (Fremling et al., 1973). These datasets include 1897 soundings completed as part of the Mississippi River Commission Survey (USACE, 1895), the 1931 Brown Survey (USACE, 1931), a 1972 survey (Fremling et al.

, 2002, Kershaw et al., 2003 and Wroe et al., 2004). Climate change proponents argue

that only a small number of extinct megafauna have been demonstrated to overlap with humans and that the bulk of extinctions occurred prior to human arrival, questioning Roberts et al.’s (2001) terminal extinction date (Field et al., 2008). In the Americas and Eurasia, warming at the end of the Last Glacial Maximum (LGM, ca. Gemcitabine ic50 18,000 years ago) resulted in rapid changes to climate and vegetation communities during the Pleistocene–Holocene transition, creating a set of environmental changes to which megafauna were unable to adapt (Graham and Grimm, 1990, Guthrie, 2003 and Guthrie, 2006). Extinctions in the New World may have been further affected by the onset of the learn more Younger Dryas, a 1000-year cooling event, which exacerbated shifts in vegetation communities. Much of the climate change model hinges on dietary assumptions about Pleistocene herbivores, and to some degree, carnivores. A variety

of new studies are testing these assumptions using genetic (mtDNA), morphologic, and isotopic (δ 13C and δ 15N) data. North American proboscideans (e.g., mammoths, mastodons) and camelids had very different and specialized diets that may have made them vulnerable to rapid climate change and vegetation shifts, for example, but carbon isotope studies of tooth enamel suggest that C4 grasslands that supported large herbivores generally remained intact during glacial to interglacial transitions (Connin et al., 1998, Koch et al., 1994, Koch et al., 1998 and Koch et al., 2004). Patterns of specialization Uroporphyrinogen III synthase have also been found with North American carnivore species. The species with the greatest extinction vulnerability tended to be the largest and most carnivorous of their families (e.g., dire wolves, saber-tooth cats, short-faced bears). The smaller, more generalized species (e.g., gray wolves, puma and bobcats, and black and brown bears) survived into the Holocene (Leonard et al.,

2007 and Van Valkenburgh and Hertel, 1993). Other studies of environmental changes across the Pleistocene–Holocene transition have suggested that climate change is not a sufficient explanation for megafaunal extinctions. Martínez-Meyer et al. (2004) found, for example, that the reduction of habitable niches for eight megafauna taxa in North America is insufficient to explain their extinction. Pollen records further show that megafaunal extinctions in Eurasia and the Americas coincided with rapid vegetational shifts, but the link between vegetation changes and extinctions in Australia is much less clear (Barnosky et al., 2004). Although comprehensive studies are needed, current pollen records also suggest that Pleistocene–Holocene changes in vegetation were not substantially different from previous glacial–interglacial cycles (Koch and Barnosky, 2006:225–226; also see Robinson et al., 2005).